lemon/list_graph.h
author Peter Kovacs <kpeter@inf.elte.hu>
Sun, 23 Aug 2009 11:11:49 +0200
changeset 737 9d6c3e8b2421
parent 735 853fcddcf282
child 738 456fa5bc3256
permissions -rw-r--r--
Add a resize() function to HypercubeGraph (#311)
just like the similar functions in other static graph structures,
and extend the test files to check these functions.
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2009
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_LIST_GRAPH_H
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#define LEMON_LIST_GRAPH_H
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///\ingroup graphs
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///\file
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///\brief ListDigraph and ListGraph classes.
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#include <lemon/core.h>
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#include <lemon/error.h>
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#include <lemon/bits/graph_extender.h>
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#include <vector>
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#include <list>
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namespace lemon {
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  class ListDigraphBase {
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  protected:
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    struct NodeT {
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      int first_in, first_out;
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      int prev, next;
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    };
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    struct ArcT {
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      int target, source;
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      int prev_in, prev_out;
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      int next_in, next_out;
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    };
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    std::vector<NodeT> nodes;
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    int first_node;
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    int first_free_node;
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    std::vector<ArcT> arcs;
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    int first_free_arc;
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  public:
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    typedef ListDigraphBase Digraph;
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    class Node {
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      friend class ListDigraphBase;
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    protected:
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      int id;
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      explicit Node(int pid) { id = pid;}
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    public:
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      Node() {}
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      Node (Invalid) { id = -1; }
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      bool operator==(const Node& node) const {return id == node.id;}
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      bool operator!=(const Node& node) const {return id != node.id;}
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      bool operator<(const Node& node) const {return id < node.id;}
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    };
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    class Arc {
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      friend class ListDigraphBase;
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    protected:
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      int id;
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      explicit Arc(int pid) { id = pid;}
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    public:
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      Arc() {}
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      Arc (Invalid) { id = -1; }
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      bool operator==(const Arc& arc) const {return id == arc.id;}
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      bool operator!=(const Arc& arc) const {return id != arc.id;}
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      bool operator<(const Arc& arc) const {return id < arc.id;}
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    };
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    ListDigraphBase()
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      : nodes(), first_node(-1),
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        first_free_node(-1), arcs(), first_free_arc(-1) {}
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    int maxNodeId() const { return nodes.size()-1; }
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    int maxArcId() const { return arcs.size()-1; }
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    Node source(Arc e) const { return Node(arcs[e.id].source); }
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    Node target(Arc e) const { return Node(arcs[e.id].target); }
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    void first(Node& node) const {
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      node.id = first_node;
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    }
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    void next(Node& node) const {
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      node.id = nodes[node.id].next;
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    }
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    void first(Arc& arc) const {
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      int n;
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      for(n = first_node;
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          n!=-1 && nodes[n].first_in == -1;
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          n = nodes[n].next) {}
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      arc.id = (n == -1) ? -1 : nodes[n].first_in;
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    }
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    void next(Arc& arc) const {
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      if (arcs[arc.id].next_in != -1) {
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        arc.id = arcs[arc.id].next_in;
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      } else {
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        int n;
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        for(n = nodes[arcs[arc.id].target].next;
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            n!=-1 && nodes[n].first_in == -1;
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            n = nodes[n].next) {}
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        arc.id = (n == -1) ? -1 : nodes[n].first_in;
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      }
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    }
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    void firstOut(Arc &e, const Node& v) const {
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      e.id = nodes[v.id].first_out;
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    }
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    void nextOut(Arc &e) const {
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      e.id=arcs[e.id].next_out;
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    }
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    void firstIn(Arc &e, const Node& v) const {
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      e.id = nodes[v.id].first_in;
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    }
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    void nextIn(Arc &e) const {
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      e.id=arcs[e.id].next_in;
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    }
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    static int id(Node v) { return v.id; }
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    static int id(Arc e) { return e.id; }
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    static Node nodeFromId(int id) { return Node(id);}
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    static Arc arcFromId(int id) { return Arc(id);}
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    bool valid(Node n) const {
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      return n.id >= 0 && n.id < static_cast<int>(nodes.size()) &&
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        nodes[n.id].prev != -2;
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    }
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    bool valid(Arc a) const {
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      return a.id >= 0 && a.id < static_cast<int>(arcs.size()) &&
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        arcs[a.id].prev_in != -2;
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    }
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    Node addNode() {
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      int n;
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      if(first_free_node==-1) {
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        n = nodes.size();
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        nodes.push_back(NodeT());
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      } else {
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        n = first_free_node;
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        first_free_node = nodes[n].next;
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      }
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      nodes[n].next = first_node;
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      if(first_node != -1) nodes[first_node].prev = n;
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      first_node = n;
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      nodes[n].prev = -1;
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      nodes[n].first_in = nodes[n].first_out = -1;
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      return Node(n);
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    }
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    Arc addArc(Node u, Node v) {
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      int n;
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      if (first_free_arc == -1) {
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        n = arcs.size();
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        arcs.push_back(ArcT());
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      } else {
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        n = first_free_arc;
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        first_free_arc = arcs[n].next_in;
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      }
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      arcs[n].source = u.id;
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      arcs[n].target = v.id;
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      arcs[n].next_out = nodes[u.id].first_out;
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      if(nodes[u.id].first_out != -1) {
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        arcs[nodes[u.id].first_out].prev_out = n;
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      }
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      arcs[n].next_in = nodes[v.id].first_in;
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      if(nodes[v.id].first_in != -1) {
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        arcs[nodes[v.id].first_in].prev_in = n;
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      }
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      arcs[n].prev_in = arcs[n].prev_out = -1;
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      nodes[u.id].first_out = nodes[v.id].first_in = n;
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      return Arc(n);
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    }
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    void erase(const Node& node) {
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      int n = node.id;
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      if(nodes[n].next != -1) {
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        nodes[nodes[n].next].prev = nodes[n].prev;
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      }
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      if(nodes[n].prev != -1) {
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        nodes[nodes[n].prev].next = nodes[n].next;
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      } else {
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        first_node = nodes[n].next;
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      }
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      nodes[n].next = first_free_node;
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      first_free_node = n;
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      nodes[n].prev = -2;
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    }
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    void erase(const Arc& arc) {
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      int n = arc.id;
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      if(arcs[n].next_in!=-1) {
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        arcs[arcs[n].next_in].prev_in = arcs[n].prev_in;
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      }
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      if(arcs[n].prev_in!=-1) {
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        arcs[arcs[n].prev_in].next_in = arcs[n].next_in;
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      } else {
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        nodes[arcs[n].target].first_in = arcs[n].next_in;
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      }
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      if(arcs[n].next_out!=-1) {
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        arcs[arcs[n].next_out].prev_out = arcs[n].prev_out;
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      }
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      if(arcs[n].prev_out!=-1) {
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        arcs[arcs[n].prev_out].next_out = arcs[n].next_out;
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      } else {
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        nodes[arcs[n].source].first_out = arcs[n].next_out;
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      }
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      arcs[n].next_in = first_free_arc;
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      first_free_arc = n;
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      arcs[n].prev_in = -2;
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    }
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    void clear() {
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      arcs.clear();
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      nodes.clear();
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      first_node = first_free_node = first_free_arc = -1;
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    }
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  protected:
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    void changeTarget(Arc e, Node n)
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    {
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      if(arcs[e.id].next_in != -1)
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        arcs[arcs[e.id].next_in].prev_in = arcs[e.id].prev_in;
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      if(arcs[e.id].prev_in != -1)
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        arcs[arcs[e.id].prev_in].next_in = arcs[e.id].next_in;
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      else nodes[arcs[e.id].target].first_in = arcs[e.id].next_in;
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      if (nodes[n.id].first_in != -1) {
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        arcs[nodes[n.id].first_in].prev_in = e.id;
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      }
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      arcs[e.id].target = n.id;
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      arcs[e.id].prev_in = -1;
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      arcs[e.id].next_in = nodes[n.id].first_in;
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      nodes[n.id].first_in = e.id;
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    }
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    void changeSource(Arc e, Node n)
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    {
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      if(arcs[e.id].next_out != -1)
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        arcs[arcs[e.id].next_out].prev_out = arcs[e.id].prev_out;
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      if(arcs[e.id].prev_out != -1)
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        arcs[arcs[e.id].prev_out].next_out = arcs[e.id].next_out;
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      else nodes[arcs[e.id].source].first_out = arcs[e.id].next_out;
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      if (nodes[n.id].first_out != -1) {
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        arcs[nodes[n.id].first_out].prev_out = e.id;
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      }
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      arcs[e.id].source = n.id;
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      arcs[e.id].prev_out = -1;
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      arcs[e.id].next_out = nodes[n.id].first_out;
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      nodes[n.id].first_out = e.id;
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    }
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  };
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  typedef DigraphExtender<ListDigraphBase> ExtendedListDigraphBase;
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  /// \addtogroup graphs
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  /// @{
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  ///A general directed graph structure.
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  ///\ref ListDigraph is a versatile and fast directed graph
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  ///implementation based on linked lists that are stored in
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  ///\c std::vector structures.
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  ///
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  ///This type fully conforms to the \ref concepts::Digraph "Digraph concept"
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  ///and it also provides several useful additional functionalities.
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  ///Most of its member functions and nested classes are documented
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  ///only in the concept class.
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  ///
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  ///\sa concepts::Digraph
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  ///\sa ListGraph
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  class ListDigraph : public ExtendedListDigraphBase {
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    typedef ExtendedListDigraphBase Parent;
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  private:
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    /// Digraphs are \e not copy constructible. Use DigraphCopy instead.
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    ListDigraph(const ListDigraph &) :ExtendedListDigraphBase() {};
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    /// \brief Assignment of a digraph to another one is \e not allowed.
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    /// Use DigraphCopy instead.
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    void operator=(const ListDigraph &) {}
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  public:
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    /// Constructor
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    /// Constructor.
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    ///
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    ListDigraph() {}
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    ///Add a new node to the digraph.
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    ///This function adds a new node to the digraph.
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    ///\return The new node.
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    Node addNode() { return Parent::addNode(); }
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    ///Add a new arc to the digraph.
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    ///This function adds a new arc to the digraph with source node \c s
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    ///and target node \c t.
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    ///\return The new arc.
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    Arc addArc(Node s, Node t) {
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      return Parent::addArc(s, t);
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    }
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    ///\brief Erase a node from the digraph.
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    ///
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    ///This function erases the given node from the digraph.
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    void erase(Node n) { Parent::erase(n); }
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    ///\brief Erase an arc from the digraph.
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    ///
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    ///This function erases the given arc from the digraph.
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    void erase(Arc a) { Parent::erase(a); }
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    /// Node validity check
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    /// This function gives back \c true if the given node is valid,
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    /// i.e. it is a real node of the digraph.
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    ///
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    /// \warning A removed node could become valid again if new nodes are
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    /// added to the digraph.
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    bool valid(Node n) const { return Parent::valid(n); }
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    /// Arc validity check
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    /// This function gives back \c true if the given arc is valid,
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    /// i.e. it is a real arc of the digraph.
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    ///
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    /// \warning A removed arc could become valid again if new arcs are
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    /// added to the digraph.
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    bool valid(Arc a) const { return Parent::valid(a); }
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    /// Change the target node of an arc
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    /// This function changes the target node of the given arc \c a to \c n.
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    ///
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    ///\note \c ArcIt and \c OutArcIt iterators referencing the changed
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    ///arc remain valid, however \c InArcIt iterators are invalidated.
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    ///
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    ///\warning This functionality cannot be used together with the Snapshot
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    ///feature.
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    void changeTarget(Arc a, Node n) {
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      Parent::changeTarget(a,n);
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    }
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    /// Change the source node of an arc
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    /// This function changes the source node of the given arc \c a to \c n.
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    ///
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    ///\note \c InArcIt iterators referencing the changed arc remain
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    ///valid, however \c ArcIt and \c OutArcIt iterators are invalidated.
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    ///
deba@57
   404
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   405
    ///feature.
deba@235
   406
    void changeSource(Arc a, Node n) {
deba@235
   407
      Parent::changeSource(a,n);
deba@57
   408
    }
deba@57
   409
kpeter@735
   410
    /// Reverse the direction of an arc.
deba@57
   411
kpeter@735
   412
    /// This function reverses the direction of the given arc.
kpeter@735
   413
    ///\note \c ArcIt, \c OutArcIt and \c InArcIt iterators referencing
kpeter@735
   414
    ///the changed arc are invalidated.
kpeter@73
   415
    ///
deba@57
   416
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   417
    ///feature.
kpeter@735
   418
    void reverseArc(Arc a) {
kpeter@735
   419
      Node t=target(a);
kpeter@735
   420
      changeTarget(a,source(a));
kpeter@735
   421
      changeSource(a,t);
deba@57
   422
    }
deba@57
   423
deba@57
   424
    ///Contract two nodes.
deba@57
   425
kpeter@735
   426
    ///This function contracts the given two nodes.
kpeter@735
   427
    ///Node \c v is removed, but instead of deleting its
kpeter@735
   428
    ///incident arcs, they are joined to node \c u.
kpeter@735
   429
    ///If the last parameter \c r is \c true (this is the default value),
kpeter@735
   430
    ///then the newly created loops are removed.
deba@57
   431
    ///
kpeter@735
   432
    ///\note The moved arcs are joined to node \c u using changeSource()
kpeter@735
   433
    ///or changeTarget(), thus \c ArcIt and \c OutArcIt iterators are
kpeter@735
   434
    ///invalidated for the outgoing arcs of node \c v and \c InArcIt
kpeter@735
   435
    ///iterators are invalidated for the incomming arcs of \c v.
kpeter@735
   436
    ///Moreover all iterators referencing node \c v or the removed 
kpeter@735
   437
    ///loops are also invalidated. Other iterators remain valid.
kpeter@73
   438
    ///
deba@57
   439
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   440
    ///feature.
kpeter@735
   441
    void contract(Node u, Node v, bool r = true)
deba@57
   442
    {
kpeter@735
   443
      for(OutArcIt e(*this,v);e!=INVALID;) {
alpar@209
   444
        OutArcIt f=e;
alpar@209
   445
        ++f;
kpeter@735
   446
        if(r && target(e)==u) erase(e);
kpeter@735
   447
        else changeSource(e,u);
alpar@209
   448
        e=f;
deba@57
   449
      }
kpeter@735
   450
      for(InArcIt e(*this,v);e!=INVALID;) {
alpar@209
   451
        InArcIt f=e;
alpar@209
   452
        ++f;
kpeter@735
   453
        if(r && source(e)==u) erase(e);
kpeter@735
   454
        else changeTarget(e,u);
alpar@209
   455
        e=f;
deba@57
   456
      }
kpeter@735
   457
      erase(v);
deba@57
   458
    }
deba@57
   459
deba@57
   460
    ///Split a node.
deba@57
   461
kpeter@735
   462
    ///This function splits the given node. First, a new node is added
kpeter@735
   463
    ///to the digraph, then the source of each outgoing arc of node \c n
kpeter@735
   464
    ///is moved to this new node.
kpeter@735
   465
    ///If the second parameter \c connect is \c true (this is the default
kpeter@735
   466
    ///value), then a new arc from node \c n to the newly created node
kpeter@735
   467
    ///is also added.
deba@57
   468
    ///\return The newly created node.
deba@57
   469
    ///
kpeter@735
   470
    ///\note \c ArcIt and \c OutArcIt iterators referencing the outgoing
kpeter@735
   471
    ///arcs of node \c n are invalidated. Other iterators remain valid.
deba@57
   472
    ///
kpeter@735
   473
    ///\warning This functionality cannot be used together with the
kpeter@73
   474
    ///Snapshot feature.
deba@57
   475
    Node split(Node n, bool connect = true) {
deba@57
   476
      Node b = addNode();
deba@57
   477
      for(OutArcIt e(*this,n);e!=INVALID;) {
kpeter@212
   478
        OutArcIt f=e;
alpar@209
   479
        ++f;
alpar@209
   480
        changeSource(e,b);
alpar@209
   481
        e=f;
deba@57
   482
      }
deba@57
   483
      if (connect) addArc(n,b);
deba@57
   484
      return b;
deba@57
   485
    }
alpar@209
   486
deba@57
   487
    ///Split an arc.
deba@57
   488
kpeter@735
   489
    ///This function splits the given arc. First, a new node \c v is
kpeter@735
   490
    ///added to the digraph, then the target node of the original arc
kpeter@735
   491
    ///is set to \c v. Finally, an arc from \c v to the original target
kpeter@735
   492
    ///is added.
kpeter@735
   493
    ///\return The newly created node.
kpeter@73
   494
    ///
kpeter@735
   495
    ///\note \c InArcIt iterators referencing the original arc are
kpeter@735
   496
    ///invalidated. Other iterators remain valid.
kpeter@73
   497
    ///
kpeter@73
   498
    ///\warning This functionality cannot be used together with the
kpeter@73
   499
    ///Snapshot feature.
kpeter@735
   500
    Node split(Arc a) {
kpeter@735
   501
      Node v = addNode();
kpeter@735
   502
      addArc(v,target(a));
kpeter@735
   503
      changeTarget(a,v);
kpeter@735
   504
      return v;
deba@57
   505
    }
alpar@209
   506
kpeter@735
   507
    ///Clear the digraph.
kpeter@735
   508
kpeter@735
   509
    ///This function erases all nodes and arcs from the digraph.
kpeter@735
   510
    ///
kpeter@735
   511
    void clear() {
kpeter@735
   512
      Parent::clear();
kpeter@735
   513
    }
kpeter@735
   514
kpeter@735
   515
    /// Reserve memory for nodes.
kpeter@735
   516
kpeter@735
   517
    /// Using this function, it is possible to avoid superfluous memory
kpeter@735
   518
    /// allocation: if you know that the digraph you want to build will
kpeter@735
   519
    /// be large (e.g. it will contain millions of nodes and/or arcs),
kpeter@735
   520
    /// then it is worth reserving space for this amount before starting
kpeter@735
   521
    /// to build the digraph.
kpeter@735
   522
    /// \sa reserveArc()
kpeter@735
   523
    void reserveNode(int n) { nodes.reserve(n); };
kpeter@735
   524
kpeter@735
   525
    /// Reserve memory for arcs.
kpeter@735
   526
kpeter@735
   527
    /// Using this function, it is possible to avoid superfluous memory
kpeter@735
   528
    /// allocation: if you know that the digraph you want to build will
kpeter@735
   529
    /// be large (e.g. it will contain millions of nodes and/or arcs),
kpeter@735
   530
    /// then it is worth reserving space for this amount before starting
kpeter@735
   531
    /// to build the digraph.
kpeter@735
   532
    /// \sa reserveNode()
kpeter@735
   533
    void reserveArc(int m) { arcs.reserve(m); };
kpeter@735
   534
deba@57
   535
    /// \brief Class to make a snapshot of the digraph and restore
kpeter@73
   536
    /// it later.
deba@57
   537
    ///
kpeter@73
   538
    /// Class to make a snapshot of the digraph and restore it later.
deba@57
   539
    ///
deba@57
   540
    /// The newly added nodes and arcs can be removed using the
deba@57
   541
    /// restore() function.
deba@57
   542
    ///
kpeter@735
   543
    /// \note After a state is restored, you cannot restore a later state, 
kpeter@735
   544
    /// i.e. you cannot add the removed nodes and arcs again using
kpeter@735
   545
    /// another Snapshot instance.
kpeter@735
   546
    ///
kpeter@735
   547
    /// \warning Node and arc deletions and other modifications (e.g.
kpeter@735
   548
    /// reversing, contracting, splitting arcs or nodes) cannot be
alpar@209
   549
    /// restored. These events invalidate the snapshot.
kpeter@735
   550
    /// However the arcs and nodes that were added to the digraph after
kpeter@735
   551
    /// making the current snapshot can be removed without invalidating it.
deba@57
   552
    class Snapshot {
deba@57
   553
    protected:
deba@57
   554
deba@57
   555
      typedef Parent::NodeNotifier NodeNotifier;
deba@57
   556
deba@57
   557
      class NodeObserverProxy : public NodeNotifier::ObserverBase {
deba@57
   558
      public:
deba@57
   559
deba@57
   560
        NodeObserverProxy(Snapshot& _snapshot)
deba@57
   561
          : snapshot(_snapshot) {}
deba@57
   562
deba@57
   563
        using NodeNotifier::ObserverBase::attach;
deba@57
   564
        using NodeNotifier::ObserverBase::detach;
deba@57
   565
        using NodeNotifier::ObserverBase::attached;
alpar@209
   566
deba@57
   567
      protected:
alpar@209
   568
deba@57
   569
        virtual void add(const Node& node) {
deba@57
   570
          snapshot.addNode(node);
deba@57
   571
        }
deba@57
   572
        virtual void add(const std::vector<Node>& nodes) {
deba@57
   573
          for (int i = nodes.size() - 1; i >= 0; ++i) {
deba@57
   574
            snapshot.addNode(nodes[i]);
deba@57
   575
          }
deba@57
   576
        }
deba@57
   577
        virtual void erase(const Node& node) {
deba@57
   578
          snapshot.eraseNode(node);
deba@57
   579
        }
deba@57
   580
        virtual void erase(const std::vector<Node>& nodes) {
deba@57
   581
          for (int i = 0; i < int(nodes.size()); ++i) {
deba@57
   582
            snapshot.eraseNode(nodes[i]);
deba@57
   583
          }
deba@57
   584
        }
deba@57
   585
        virtual void build() {
deba@57
   586
          Node node;
deba@57
   587
          std::vector<Node> nodes;
alpar@209
   588
          for (notifier()->first(node); node != INVALID;
deba@57
   589
               notifier()->next(node)) {
deba@57
   590
            nodes.push_back(node);
deba@57
   591
          }
deba@57
   592
          for (int i = nodes.size() - 1; i >= 0; --i) {
deba@57
   593
            snapshot.addNode(nodes[i]);
deba@57
   594
          }
deba@57
   595
        }
deba@57
   596
        virtual void clear() {
deba@57
   597
          Node node;
alpar@209
   598
          for (notifier()->first(node); node != INVALID;
deba@57
   599
               notifier()->next(node)) {
deba@57
   600
            snapshot.eraseNode(node);
deba@57
   601
          }
deba@57
   602
        }
deba@57
   603
deba@57
   604
        Snapshot& snapshot;
deba@57
   605
      };
deba@57
   606
deba@57
   607
      class ArcObserverProxy : public ArcNotifier::ObserverBase {
deba@57
   608
      public:
deba@57
   609
deba@57
   610
        ArcObserverProxy(Snapshot& _snapshot)
deba@57
   611
          : snapshot(_snapshot) {}
deba@57
   612
deba@57
   613
        using ArcNotifier::ObserverBase::attach;
deba@57
   614
        using ArcNotifier::ObserverBase::detach;
deba@57
   615
        using ArcNotifier::ObserverBase::attached;
alpar@209
   616
deba@57
   617
      protected:
deba@57
   618
deba@57
   619
        virtual void add(const Arc& arc) {
deba@57
   620
          snapshot.addArc(arc);
deba@57
   621
        }
deba@57
   622
        virtual void add(const std::vector<Arc>& arcs) {
deba@57
   623
          for (int i = arcs.size() - 1; i >= 0; ++i) {
deba@57
   624
            snapshot.addArc(arcs[i]);
deba@57
   625
          }
deba@57
   626
        }
deba@57
   627
        virtual void erase(const Arc& arc) {
deba@57
   628
          snapshot.eraseArc(arc);
deba@57
   629
        }
deba@57
   630
        virtual void erase(const std::vector<Arc>& arcs) {
deba@57
   631
          for (int i = 0; i < int(arcs.size()); ++i) {
deba@57
   632
            snapshot.eraseArc(arcs[i]);
deba@57
   633
          }
deba@57
   634
        }
deba@57
   635
        virtual void build() {
deba@57
   636
          Arc arc;
deba@57
   637
          std::vector<Arc> arcs;
alpar@209
   638
          for (notifier()->first(arc); arc != INVALID;
deba@57
   639
               notifier()->next(arc)) {
deba@57
   640
            arcs.push_back(arc);
deba@57
   641
          }
deba@57
   642
          for (int i = arcs.size() - 1; i >= 0; --i) {
deba@57
   643
            snapshot.addArc(arcs[i]);
deba@57
   644
          }
deba@57
   645
        }
deba@57
   646
        virtual void clear() {
deba@57
   647
          Arc arc;
alpar@209
   648
          for (notifier()->first(arc); arc != INVALID;
deba@57
   649
               notifier()->next(arc)) {
deba@57
   650
            snapshot.eraseArc(arc);
deba@57
   651
          }
deba@57
   652
        }
deba@57
   653
deba@57
   654
        Snapshot& snapshot;
deba@57
   655
      };
alpar@209
   656
deba@57
   657
      ListDigraph *digraph;
deba@57
   658
deba@57
   659
      NodeObserverProxy node_observer_proxy;
deba@57
   660
      ArcObserverProxy arc_observer_proxy;
deba@57
   661
deba@57
   662
      std::list<Node> added_nodes;
deba@57
   663
      std::list<Arc> added_arcs;
deba@57
   664
deba@57
   665
deba@57
   666
      void addNode(const Node& node) {
alpar@209
   667
        added_nodes.push_front(node);
deba@57
   668
      }
deba@57
   669
      void eraseNode(const Node& node) {
alpar@209
   670
        std::list<Node>::iterator it =
deba@57
   671
          std::find(added_nodes.begin(), added_nodes.end(), node);
deba@57
   672
        if (it == added_nodes.end()) {
deba@57
   673
          clear();
deba@57
   674
          arc_observer_proxy.detach();
deba@57
   675
          throw NodeNotifier::ImmediateDetach();
deba@57
   676
        } else {
deba@57
   677
          added_nodes.erase(it);
deba@57
   678
        }
deba@57
   679
      }
deba@57
   680
deba@57
   681
      void addArc(const Arc& arc) {
alpar@209
   682
        added_arcs.push_front(arc);
deba@57
   683
      }
deba@57
   684
      void eraseArc(const Arc& arc) {
alpar@209
   685
        std::list<Arc>::iterator it =
deba@57
   686
          std::find(added_arcs.begin(), added_arcs.end(), arc);
deba@57
   687
        if (it == added_arcs.end()) {
deba@57
   688
          clear();
alpar@209
   689
          node_observer_proxy.detach();
deba@57
   690
          throw ArcNotifier::ImmediateDetach();
deba@57
   691
        } else {
deba@57
   692
          added_arcs.erase(it);
alpar@209
   693
        }
deba@57
   694
      }
deba@57
   695
deba@57
   696
      void attach(ListDigraph &_digraph) {
alpar@209
   697
        digraph = &_digraph;
alpar@209
   698
        node_observer_proxy.attach(digraph->notifier(Node()));
deba@57
   699
        arc_observer_proxy.attach(digraph->notifier(Arc()));
deba@57
   700
      }
alpar@209
   701
deba@57
   702
      void detach() {
alpar@209
   703
        node_observer_proxy.detach();
alpar@209
   704
        arc_observer_proxy.detach();
deba@57
   705
      }
deba@57
   706
deba@57
   707
      bool attached() const {
deba@57
   708
        return node_observer_proxy.attached();
deba@57
   709
      }
deba@57
   710
deba@57
   711
      void clear() {
deba@57
   712
        added_nodes.clear();
alpar@209
   713
        added_arcs.clear();
deba@57
   714
      }
deba@57
   715
deba@57
   716
    public:
deba@57
   717
deba@57
   718
      /// \brief Default constructor.
deba@57
   719
      ///
deba@57
   720
      /// Default constructor.
kpeter@735
   721
      /// You have to call save() to actually make a snapshot.
alpar@209
   722
      Snapshot()
alpar@209
   723
        : digraph(0), node_observer_proxy(*this),
deba@57
   724
          arc_observer_proxy(*this) {}
alpar@209
   725
deba@57
   726
      /// \brief Constructor that immediately makes a snapshot.
alpar@209
   727
      ///
kpeter@735
   728
      /// This constructor immediately makes a snapshot of the given digraph.
kpeter@735
   729
      Snapshot(ListDigraph &gr)
alpar@209
   730
        : node_observer_proxy(*this),
deba@57
   731
          arc_observer_proxy(*this) {
kpeter@735
   732
        attach(gr);
deba@57
   733
      }
alpar@209
   734
deba@57
   735
      /// \brief Make a snapshot.
deba@57
   736
      ///
kpeter@735
   737
      /// This function makes a snapshot of the given digraph.
kpeter@735
   738
      /// It can be called more than once. In case of a repeated
deba@57
   739
      /// call, the previous snapshot gets lost.
kpeter@735
   740
      void save(ListDigraph &gr) {
deba@57
   741
        if (attached()) {
deba@57
   742
          detach();
deba@57
   743
          clear();
deba@57
   744
        }
kpeter@735
   745
        attach(gr);
deba@57
   746
      }
alpar@209
   747
deba@57
   748
      /// \brief Undo the changes until the last snapshot.
kpeter@735
   749
      ///
kpeter@735
   750
      /// This function undos the changes until the last snapshot
kpeter@735
   751
      /// created by save() or Snapshot(ListDigraph&).
deba@57
   752
      void restore() {
alpar@209
   753
        detach();
alpar@209
   754
        for(std::list<Arc>::iterator it = added_arcs.begin();
deba@57
   755
            it != added_arcs.end(); ++it) {
alpar@209
   756
          digraph->erase(*it);
alpar@209
   757
        }
alpar@209
   758
        for(std::list<Node>::iterator it = added_nodes.begin();
deba@57
   759
            it != added_nodes.end(); ++it) {
alpar@209
   760
          digraph->erase(*it);
alpar@209
   761
        }
deba@57
   762
        clear();
deba@57
   763
      }
deba@57
   764
kpeter@735
   765
      /// \brief Returns \c true if the snapshot is valid.
deba@57
   766
      ///
kpeter@735
   767
      /// This function returns \c true if the snapshot is valid.
deba@57
   768
      bool valid() const {
deba@57
   769
        return attached();
deba@57
   770
      }
deba@57
   771
    };
alpar@209
   772
deba@57
   773
  };
deba@57
   774
deba@57
   775
  ///@}
deba@57
   776
deba@57
   777
  class ListGraphBase {
deba@57
   778
deba@57
   779
  protected:
deba@57
   780
deba@57
   781
    struct NodeT {
deba@57
   782
      int first_out;
deba@57
   783
      int prev, next;
deba@57
   784
    };
alpar@209
   785
deba@57
   786
    struct ArcT {
deba@57
   787
      int target;
deba@57
   788
      int prev_out, next_out;
deba@57
   789
    };
deba@57
   790
deba@57
   791
    std::vector<NodeT> nodes;
deba@57
   792
deba@57
   793
    int first_node;
deba@57
   794
deba@57
   795
    int first_free_node;
deba@57
   796
deba@57
   797
    std::vector<ArcT> arcs;
deba@57
   798
deba@57
   799
    int first_free_arc;
alpar@209
   800
deba@57
   801
  public:
alpar@209
   802
kpeter@617
   803
    typedef ListGraphBase Graph;
deba@57
   804
deba@57
   805
    class Node {
deba@57
   806
      friend class ListGraphBase;
deba@57
   807
    protected:
deba@57
   808
deba@57
   809
      int id;
deba@57
   810
      explicit Node(int pid) { id = pid;}
deba@57
   811
deba@57
   812
    public:
deba@57
   813
      Node() {}
deba@57
   814
      Node (Invalid) { id = -1; }
deba@57
   815
      bool operator==(const Node& node) const {return id == node.id;}
deba@57
   816
      bool operator!=(const Node& node) const {return id != node.id;}
deba@57
   817
      bool operator<(const Node& node) const {return id < node.id;}
deba@57
   818
    };
deba@57
   819
deba@57
   820
    class Edge {
deba@57
   821
      friend class ListGraphBase;
deba@57
   822
    protected:
deba@57
   823
deba@57
   824
      int id;
deba@57
   825
      explicit Edge(int pid) { id = pid;}
deba@57
   826
deba@57
   827
    public:
deba@57
   828
      Edge() {}
deba@57
   829
      Edge (Invalid) { id = -1; }
kpeter@73
   830
      bool operator==(const Edge& edge) const {return id == edge.id;}
kpeter@73
   831
      bool operator!=(const Edge& edge) const {return id != edge.id;}
kpeter@73
   832
      bool operator<(const Edge& edge) const {return id < edge.id;}
deba@57
   833
    };
deba@57
   834
deba@57
   835
    class Arc {
deba@57
   836
      friend class ListGraphBase;
deba@57
   837
    protected:
deba@57
   838
deba@57
   839
      int id;
deba@57
   840
      explicit Arc(int pid) { id = pid;}
deba@57
   841
deba@57
   842
    public:
kpeter@329
   843
      operator Edge() const {
kpeter@329
   844
        return id != -1 ? edgeFromId(id / 2) : INVALID;
deba@238
   845
      }
deba@57
   846
deba@57
   847
      Arc() {}
deba@57
   848
      Arc (Invalid) { id = -1; }
deba@57
   849
      bool operator==(const Arc& arc) const {return id == arc.id;}
deba@57
   850
      bool operator!=(const Arc& arc) const {return id != arc.id;}
deba@57
   851
      bool operator<(const Arc& arc) const {return id < arc.id;}
deba@57
   852
    };
deba@57
   853
deba@57
   854
    ListGraphBase()
deba@57
   855
      : nodes(), first_node(-1),
alpar@209
   856
        first_free_node(-1), arcs(), first_free_arc(-1) {}
deba@57
   857
alpar@209
   858
alpar@209
   859
    int maxNodeId() const { return nodes.size()-1; }
deba@57
   860
    int maxEdgeId() const { return arcs.size() / 2 - 1; }
deba@57
   861
    int maxArcId() const { return arcs.size()-1; }
deba@57
   862
deba@57
   863
    Node source(Arc e) const { return Node(arcs[e.id ^ 1].target); }
deba@57
   864
    Node target(Arc e) const { return Node(arcs[e.id].target); }
deba@57
   865
deba@57
   866
    Node u(Edge e) const { return Node(arcs[2 * e.id].target); }
deba@57
   867
    Node v(Edge e) const { return Node(arcs[2 * e.id + 1].target); }
deba@57
   868
deba@57
   869
    static bool direction(Arc e) {
deba@57
   870
      return (e.id & 1) == 1;
deba@57
   871
    }
deba@57
   872
deba@57
   873
    static Arc direct(Edge e, bool d) {
deba@57
   874
      return Arc(e.id * 2 + (d ? 1 : 0));
deba@57
   875
    }
deba@57
   876
alpar@209
   877
    void first(Node& node) const {
deba@57
   878
      node.id = first_node;
deba@57
   879
    }
deba@57
   880
deba@57
   881
    void next(Node& node) const {
deba@57
   882
      node.id = nodes[node.id].next;
deba@57
   883
    }
deba@57
   884
alpar@209
   885
    void first(Arc& e) const {
deba@57
   886
      int n = first_node;
deba@57
   887
      while (n != -1 && nodes[n].first_out == -1) {
deba@57
   888
        n = nodes[n].next;
deba@57
   889
      }
deba@57
   890
      e.id = (n == -1) ? -1 : nodes[n].first_out;
deba@57
   891
    }
deba@57
   892
deba@57
   893
    void next(Arc& e) const {
deba@57
   894
      if (arcs[e.id].next_out != -1) {
alpar@209
   895
        e.id = arcs[e.id].next_out;
deba@57
   896
      } else {
alpar@209
   897
        int n = nodes[arcs[e.id ^ 1].target].next;
deba@57
   898
        while(n != -1 && nodes[n].first_out == -1) {
deba@57
   899
          n = nodes[n].next;
deba@57
   900
        }
alpar@209
   901
        e.id = (n == -1) ? -1 : nodes[n].first_out;
alpar@209
   902
      }
deba@57
   903
    }
deba@57
   904
alpar@209
   905
    void first(Edge& e) const {
deba@57
   906
      int n = first_node;
deba@57
   907
      while (n != -1) {
deba@57
   908
        e.id = nodes[n].first_out;
deba@57
   909
        while ((e.id & 1) != 1) {
deba@57
   910
          e.id = arcs[e.id].next_out;
deba@57
   911
        }
deba@57
   912
        if (e.id != -1) {
deba@57
   913
          e.id /= 2;
deba@57
   914
          return;
alpar@209
   915
        }
deba@57
   916
        n = nodes[n].next;
deba@57
   917
      }
deba@57
   918
      e.id = -1;
deba@57
   919
    }
deba@57
   920
deba@57
   921
    void next(Edge& e) const {
deba@57
   922
      int n = arcs[e.id * 2].target;
deba@57
   923
      e.id = arcs[(e.id * 2) | 1].next_out;
deba@57
   924
      while ((e.id & 1) != 1) {
deba@57
   925
        e.id = arcs[e.id].next_out;
deba@57
   926
      }
deba@57
   927
      if (e.id != -1) {
deba@57
   928
        e.id /= 2;
deba@57
   929
        return;
alpar@209
   930
      }
deba@57
   931
      n = nodes[n].next;
deba@57
   932
      while (n != -1) {
deba@57
   933
        e.id = nodes[n].first_out;
deba@57
   934
        while ((e.id & 1) != 1) {
deba@57
   935
          e.id = arcs[e.id].next_out;
deba@57
   936
        }
deba@57
   937
        if (e.id != -1) {
deba@57
   938
          e.id /= 2;
deba@57
   939
          return;
alpar@209
   940
        }
deba@57
   941
        n = nodes[n].next;
deba@57
   942
      }
deba@57
   943
      e.id = -1;
deba@57
   944
    }
deba@57
   945
deba@57
   946
    void firstOut(Arc &e, const Node& v) const {
deba@57
   947
      e.id = nodes[v.id].first_out;
deba@57
   948
    }
deba@57
   949
    void nextOut(Arc &e) const {
deba@57
   950
      e.id = arcs[e.id].next_out;
deba@57
   951
    }
deba@57
   952
deba@57
   953
    void firstIn(Arc &e, const Node& v) const {
deba@57
   954
      e.id = ((nodes[v.id].first_out) ^ 1);
deba@57
   955
      if (e.id == -2) e.id = -1;
deba@57
   956
    }
deba@57
   957
    void nextIn(Arc &e) const {
deba@57
   958
      e.id = ((arcs[e.id ^ 1].next_out) ^ 1);
deba@57
   959
      if (e.id == -2) e.id = -1;
deba@57
   960
    }
deba@57
   961
deba@57
   962
    void firstInc(Edge &e, bool& d, const Node& v) const {
kpeter@73
   963
      int a = nodes[v.id].first_out;
kpeter@73
   964
      if (a != -1 ) {
kpeter@73
   965
        e.id = a / 2;
kpeter@73
   966
        d = ((a & 1) == 1);
deba@57
   967
      } else {
deba@57
   968
        e.id = -1;
deba@57
   969
        d = true;
deba@57
   970
      }
deba@57
   971
    }
deba@57
   972
    void nextInc(Edge &e, bool& d) const {
kpeter@73
   973
      int a = (arcs[(e.id * 2) | (d ? 1 : 0)].next_out);
kpeter@73
   974
      if (a != -1 ) {
kpeter@73
   975
        e.id = a / 2;
kpeter@73
   976
        d = ((a & 1) == 1);
deba@57
   977
      } else {
deba@57
   978
        e.id = -1;
deba@57
   979
        d = true;
deba@57
   980
      }
deba@57
   981
    }
alpar@209
   982
deba@57
   983
    static int id(Node v) { return v.id; }
deba@57
   984
    static int id(Arc e) { return e.id; }
deba@57
   985
    static int id(Edge e) { return e.id; }
deba@57
   986
deba@57
   987
    static Node nodeFromId(int id) { return Node(id);}
deba@57
   988
    static Arc arcFromId(int id) { return Arc(id);}
deba@57
   989
    static Edge edgeFromId(int id) { return Edge(id);}
deba@57
   990
alpar@209
   991
    bool valid(Node n) const {
alpar@209
   992
      return n.id >= 0 && n.id < static_cast<int>(nodes.size()) &&
alpar@209
   993
        nodes[n.id].prev != -2;
deba@149
   994
    }
deba@149
   995
alpar@209
   996
    bool valid(Arc a) const {
alpar@209
   997
      return a.id >= 0 && a.id < static_cast<int>(arcs.size()) &&
alpar@209
   998
        arcs[a.id].prev_out != -2;
deba@149
   999
    }
deba@149
  1000
alpar@209
  1001
    bool valid(Edge e) const {
alpar@209
  1002
      return e.id >= 0 && 2 * e.id < static_cast<int>(arcs.size()) &&
alpar@209
  1003
        arcs[2 * e.id].prev_out != -2;
deba@149
  1004
    }
deba@149
  1005
alpar@209
  1006
    Node addNode() {
deba@57
  1007
      int n;
alpar@209
  1008
deba@57
  1009
      if(first_free_node==-1) {
alpar@209
  1010
        n = nodes.size();
alpar@209
  1011
        nodes.push_back(NodeT());
deba@57
  1012
      } else {
alpar@209
  1013
        n = first_free_node;
alpar@209
  1014
        first_free_node = nodes[n].next;
deba@57
  1015
      }
alpar@209
  1016
deba@57
  1017
      nodes[n].next = first_node;
deba@57
  1018
      if (first_node != -1) nodes[first_node].prev = n;
deba@57
  1019
      first_node = n;
deba@57
  1020
      nodes[n].prev = -1;
alpar@209
  1021
deba@57
  1022
      nodes[n].first_out = -1;
alpar@209
  1023
deba@57
  1024
      return Node(n);
deba@57
  1025
    }
alpar@209
  1026
deba@57
  1027
    Edge addEdge(Node u, Node v) {
alpar@209
  1028
      int n;
deba@57
  1029
deba@57
  1030
      if (first_free_arc == -1) {
alpar@209
  1031
        n = arcs.size();
alpar@209
  1032
        arcs.push_back(ArcT());
alpar@209
  1033
        arcs.push_back(ArcT());
deba@57
  1034
      } else {
alpar@209
  1035
        n = first_free_arc;
alpar@209
  1036
        first_free_arc = arcs[n].next_out;
deba@57
  1037
      }
alpar@209
  1038
deba@57
  1039
      arcs[n].target = u.id;
deba@57
  1040
      arcs[n | 1].target = v.id;
deba@57
  1041
deba@57
  1042
      arcs[n].next_out = nodes[v.id].first_out;
deba@57
  1043
      if (nodes[v.id].first_out != -1) {
alpar@209
  1044
        arcs[nodes[v.id].first_out].prev_out = n;
alpar@209
  1045
      }
deba@57
  1046
      arcs[n].prev_out = -1;
deba@57
  1047
      nodes[v.id].first_out = n;
alpar@209
  1048
deba@57
  1049
      arcs[n | 1].next_out = nodes[u.id].first_out;
deba@57
  1050
      if (nodes[u.id].first_out != -1) {
alpar@209
  1051
        arcs[nodes[u.id].first_out].prev_out = (n | 1);
deba@57
  1052
      }
alpar@209
  1053
      arcs[n | 1].prev_out = -1;
deba@57
  1054
      nodes[u.id].first_out = (n | 1);
deba@57
  1055
deba@57
  1056
      return Edge(n / 2);
deba@57
  1057
    }
alpar@209
  1058
deba@57
  1059
    void erase(const Node& node) {
deba@57
  1060
      int n = node.id;
alpar@209
  1061
deba@57
  1062
      if(nodes[n].next != -1) {
alpar@209
  1063
        nodes[nodes[n].next].prev = nodes[n].prev;
deba@57
  1064
      }
alpar@209
  1065
deba@57
  1066
      if(nodes[n].prev != -1) {
alpar@209
  1067
        nodes[nodes[n].prev].next = nodes[n].next;
deba@57
  1068
      } else {
alpar@209
  1069
        first_node = nodes[n].next;
deba@57
  1070
      }
alpar@209
  1071
deba@57
  1072
      nodes[n].next = first_free_node;
deba@57
  1073
      first_free_node = n;
deba@149
  1074
      nodes[n].prev = -2;
deba@57
  1075
    }
alpar@209
  1076
kpeter@73
  1077
    void erase(const Edge& edge) {
kpeter@73
  1078
      int n = edge.id * 2;
alpar@209
  1079
deba@57
  1080
      if (arcs[n].next_out != -1) {
alpar@209
  1081
        arcs[arcs[n].next_out].prev_out = arcs[n].prev_out;
alpar@209
  1082
      }
deba@57
  1083
deba@57
  1084
      if (arcs[n].prev_out != -1) {
alpar@209
  1085
        arcs[arcs[n].prev_out].next_out = arcs[n].next_out;
deba@57
  1086
      } else {
alpar@209
  1087
        nodes[arcs[n | 1].target].first_out = arcs[n].next_out;
deba@57
  1088
      }
deba@57
  1089
deba@57
  1090
      if (arcs[n | 1].next_out != -1) {
alpar@209
  1091
        arcs[arcs[n | 1].next_out].prev_out = arcs[n | 1].prev_out;
alpar@209
  1092
      }
deba@57
  1093
deba@57
  1094
      if (arcs[n | 1].prev_out != -1) {
alpar@209
  1095
        arcs[arcs[n | 1].prev_out].next_out = arcs[n | 1].next_out;
deba@57
  1096
      } else {
alpar@209
  1097
        nodes[arcs[n].target].first_out = arcs[n | 1].next_out;
deba@57
  1098
      }
alpar@209
  1099
deba@57
  1100
      arcs[n].next_out = first_free_arc;
alpar@209
  1101
      first_free_arc = n;
deba@149
  1102
      arcs[n].prev_out = -2;
deba@149
  1103
      arcs[n | 1].prev_out = -2;
deba@57
  1104
deba@57
  1105
    }
deba@57
  1106
deba@57
  1107
    void clear() {
deba@57
  1108
      arcs.clear();
deba@57
  1109
      nodes.clear();
deba@57
  1110
      first_node = first_free_node = first_free_arc = -1;
deba@57
  1111
    }
deba@57
  1112
deba@57
  1113
  protected:
deba@57
  1114
deba@235
  1115
    void changeV(Edge e, Node n) {
deba@57
  1116
      if(arcs[2 * e.id].next_out != -1) {
alpar@209
  1117
        arcs[arcs[2 * e.id].next_out].prev_out = arcs[2 * e.id].prev_out;
deba@57
  1118
      }
deba@57
  1119
      if(arcs[2 * e.id].prev_out != -1) {
alpar@209
  1120
        arcs[arcs[2 * e.id].prev_out].next_out =
deba@57
  1121
          arcs[2 * e.id].next_out;
deba@57
  1122
      } else {
alpar@209
  1123
        nodes[arcs[(2 * e.id) | 1].target].first_out =
deba@57
  1124
          arcs[2 * e.id].next_out;
deba@57
  1125
      }
deba@57
  1126
deba@57
  1127
      if (nodes[n.id].first_out != -1) {
alpar@209
  1128
        arcs[nodes[n.id].first_out].prev_out = 2 * e.id;
deba@57
  1129
      }
deba@57
  1130
      arcs[(2 * e.id) | 1].target = n.id;
deba@57
  1131
      arcs[2 * e.id].prev_out = -1;
deba@57
  1132
      arcs[2 * e.id].next_out = nodes[n.id].first_out;
deba@57
  1133
      nodes[n.id].first_out = 2 * e.id;
deba@57
  1134
    }
deba@57
  1135
deba@235
  1136
    void changeU(Edge e, Node n) {
deba@57
  1137
      if(arcs[(2 * e.id) | 1].next_out != -1) {
alpar@209
  1138
        arcs[arcs[(2 * e.id) | 1].next_out].prev_out =
deba@57
  1139
          arcs[(2 * e.id) | 1].prev_out;
deba@57
  1140
      }
deba@57
  1141
      if(arcs[(2 * e.id) | 1].prev_out != -1) {
alpar@209
  1142
        arcs[arcs[(2 * e.id) | 1].prev_out].next_out =
deba@57
  1143
          arcs[(2 * e.id) | 1].next_out;
deba@57
  1144
      } else {
alpar@209
  1145
        nodes[arcs[2 * e.id].target].first_out =
deba@57
  1146
          arcs[(2 * e.id) | 1].next_out;
deba@57
  1147
      }
deba@57
  1148
deba@57
  1149
      if (nodes[n.id].first_out != -1) {
alpar@209
  1150
        arcs[nodes[n.id].first_out].prev_out = ((2 * e.id) | 1);
deba@57
  1151
      }
deba@57
  1152
      arcs[2 * e.id].target = n.id;
deba@57
  1153
      arcs[(2 * e.id) | 1].prev_out = -1;
deba@57
  1154
      arcs[(2 * e.id) | 1].next_out = nodes[n.id].first_out;
deba@57
  1155
      nodes[n.id].first_out = ((2 * e.id) | 1);
deba@57
  1156
    }
deba@57
  1157
deba@57
  1158
  };
deba@57
  1159
deba@57
  1160
  typedef GraphExtender<ListGraphBase> ExtendedListGraphBase;
deba@57
  1161
deba@57
  1162
kpeter@73
  1163
  /// \addtogroup graphs
deba@57
  1164
  /// @{
deba@57
  1165
kpeter@73
  1166
  ///A general undirected graph structure.
deba@57
  1167
kpeter@735
  1168
  ///\ref ListGraph is a versatile and fast undirected graph
kpeter@735
  1169
  ///implementation based on linked lists that are stored in
alpar@209
  1170
  ///\c std::vector structures.
deba@57
  1171
  ///
kpeter@735
  1172
  ///This type fully conforms to the \ref concepts::Graph "Graph concept"
kpeter@735
  1173
  ///and it also provides several useful additional functionalities.
kpeter@735
  1174
  ///Most of its member functions and nested classes are documented
kpeter@73
  1175
  ///only in the concept class.
kpeter@73
  1176
  ///
kpeter@73
  1177
  ///\sa concepts::Graph
kpeter@735
  1178
  ///\sa ListDigraph
deba@57
  1179
  class ListGraph : public ExtendedListGraphBase {
kpeter@617
  1180
    typedef ExtendedListGraphBase Parent;
kpeter@617
  1181
deba@57
  1182
  private:
kpeter@735
  1183
    /// Graphs are \e not copy constructible. Use GraphCopy instead.
deba@57
  1184
    ListGraph(const ListGraph &) :ExtendedListGraphBase()  {};
kpeter@735
  1185
    /// \brief Assignment of a graph to another one is \e not allowed.
kpeter@735
  1186
    /// Use GraphCopy instead.
deba@57
  1187
    void operator=(const ListGraph &) {}
deba@57
  1188
  public:
deba@57
  1189
    /// Constructor
alpar@209
  1190
deba@57
  1191
    /// Constructor.
deba@57
  1192
    ///
deba@57
  1193
    ListGraph() {}
deba@57
  1194
kpeter@73
  1195
    typedef Parent::OutArcIt IncEdgeIt;
deba@57
  1196
kpeter@73
  1197
    /// \brief Add a new node to the graph.
deba@57
  1198
    ///
kpeter@735
  1199
    /// This function adds a new node to the graph.
kpeter@559
  1200
    /// \return The new node.
deba@57
  1201
    Node addNode() { return Parent::addNode(); }
deba@57
  1202
kpeter@73
  1203
    /// \brief Add a new edge to the graph.
deba@57
  1204
    ///
kpeter@735
  1205
    /// This function adds a new edge to the graph between nodes
kpeter@735
  1206
    /// \c u and \c v with inherent orientation from node \c u to
kpeter@735
  1207
    /// node \c v.
kpeter@559
  1208
    /// \return The new edge.
kpeter@735
  1209
    Edge addEdge(Node u, Node v) {
kpeter@735
  1210
      return Parent::addEdge(u, v);
deba@57
  1211
    }
deba@234
  1212
kpeter@735
  1213
    ///\brief Erase a node from the graph.
deba@234
  1214
    ///
kpeter@735
  1215
    /// This function erases the given node from the graph.
kpeter@735
  1216
    void erase(Node n) { Parent::erase(n); }
kpeter@735
  1217
kpeter@735
  1218
    ///\brief Erase an edge from the graph.
deba@234
  1219
    ///
kpeter@735
  1220
    /// This function erases the given edge from the graph.
kpeter@735
  1221
    void erase(Edge e) { Parent::erase(e); }
deba@149
  1222
    /// Node validity check
deba@149
  1223
kpeter@735
  1224
    /// This function gives back \c true if the given node is valid,
kpeter@735
  1225
    /// i.e. it is a real node of the graph.
deba@149
  1226
    ///
kpeter@735
  1227
    /// \warning A removed node could become valid again if new nodes are
deba@149
  1228
    /// added to the graph.
deba@149
  1229
    bool valid(Node n) const { return Parent::valid(n); }
kpeter@735
  1230
    /// Edge validity check
kpeter@735
  1231
kpeter@735
  1232
    /// This function gives back \c true if the given edge is valid,
kpeter@735
  1233
    /// i.e. it is a real edge of the graph.
kpeter@735
  1234
    ///
kpeter@735
  1235
    /// \warning A removed edge could become valid again if new edges are
kpeter@735
  1236
    /// added to the graph.
kpeter@735
  1237
    bool valid(Edge e) const { return Parent::valid(e); }
deba@149
  1238
    /// Arc validity check
deba@149
  1239
kpeter@735
  1240
    /// This function gives back \c true if the given arc is valid,
kpeter@735
  1241
    /// i.e. it is a real arc of the graph.
deba@149
  1242
    ///
kpeter@735
  1243
    /// \warning A removed arc could become valid again if new edges are
deba@149
  1244
    /// added to the graph.
deba@149
  1245
    bool valid(Arc a) const { return Parent::valid(a); }
deba@149
  1246
kpeter@735
  1247
    /// \brief Change the first node of an edge.
deba@149
  1248
    ///
kpeter@735
  1249
    /// This function changes the first node of the given edge \c e to \c n.
deba@57
  1250
    ///
kpeter@735
  1251
    ///\note \c EdgeIt and \c ArcIt iterators referencing the
kpeter@735
  1252
    ///changed edge are invalidated and all other iterators whose
kpeter@735
  1253
    ///base node is the changed node are also invalidated.
kpeter@73
  1254
    ///
kpeter@73
  1255
    ///\warning This functionality cannot be used together with the
kpeter@73
  1256
    ///Snapshot feature.
deba@235
  1257
    void changeU(Edge e, Node n) {
deba@235
  1258
      Parent::changeU(e,n);
alpar@209
  1259
    }
kpeter@735
  1260
    /// \brief Change the second node of an edge.
deba@57
  1261
    ///
kpeter@735
  1262
    /// This function changes the second node of the given edge \c e to \c n.
deba@57
  1263
    ///
kpeter@735
  1264
    ///\note \c EdgeIt iterators referencing the changed edge remain
kpeter@735
  1265
    ///valid, however \c ArcIt iterators referencing the changed edge and
kpeter@735
  1266
    ///all other iterators whose base node is the changed node are also
kpeter@735
  1267
    ///invalidated.
kpeter@73
  1268
    ///
kpeter@73
  1269
    ///\warning This functionality cannot be used together with the
kpeter@73
  1270
    ///Snapshot feature.
deba@235
  1271
    void changeV(Edge e, Node n) {
deba@235
  1272
      Parent::changeV(e,n);
deba@57
  1273
    }
kpeter@735
  1274
deba@57
  1275
    /// \brief Contract two nodes.
deba@57
  1276
    ///
kpeter@735
  1277
    /// This function contracts the given two nodes.
kpeter@735
  1278
    /// Node \c b is removed, but instead of deleting
kpeter@735
  1279
    /// its incident edges, they are joined to node \c a.
kpeter@735
  1280
    /// If the last parameter \c r is \c true (this is the default value),
kpeter@735
  1281
    /// then the newly created loops are removed.
deba@57
  1282
    ///
kpeter@735
  1283
    /// \note The moved edges are joined to node \c a using changeU()
kpeter@735
  1284
    /// or changeV(), thus all edge and arc iterators whose base node is
kpeter@735
  1285
    /// \c b are invalidated.
kpeter@735
  1286
    /// Moreover all iterators referencing node \c b or the removed 
kpeter@735
  1287
    /// loops are also invalidated. Other iterators remain valid.
kpeter@73
  1288
    ///
kpeter@73
  1289
    ///\warning This functionality cannot be used together with the
kpeter@73
  1290
    ///Snapshot feature.
deba@57
  1291
    void contract(Node a, Node b, bool r = true) {
kpeter@73
  1292
      for(IncEdgeIt e(*this, b); e!=INVALID;) {
alpar@209
  1293
        IncEdgeIt f = e; ++f;
alpar@209
  1294
        if (r && runningNode(e) == a) {
alpar@209
  1295
          erase(e);
deba@235
  1296
        } else if (u(e) == b) {
deba@235
  1297
          changeU(e, a);
alpar@209
  1298
        } else {
deba@235
  1299
          changeV(e, a);
alpar@209
  1300
        }
alpar@209
  1301
        e = f;
deba@57
  1302
      }
deba@57
  1303
      erase(b);
deba@57
  1304
    }
deba@57
  1305
kpeter@735
  1306
    ///Clear the graph.
kpeter@735
  1307
kpeter@735
  1308
    ///This function erases all nodes and arcs from the graph.
kpeter@735
  1309
    ///
kpeter@735
  1310
    void clear() {
kpeter@735
  1311
      Parent::clear();
kpeter@735
  1312
    }
deba@57
  1313
kpeter@736
  1314
    /// Reserve memory for nodes.
kpeter@736
  1315
kpeter@736
  1316
    /// Using this function, it is possible to avoid superfluous memory
kpeter@736
  1317
    /// allocation: if you know that the graph you want to build will
kpeter@736
  1318
    /// be large (e.g. it will contain millions of nodes and/or edges),
kpeter@736
  1319
    /// then it is worth reserving space for this amount before starting
kpeter@736
  1320
    /// to build the graph.
kpeter@736
  1321
    /// \sa reserveEdge()
kpeter@736
  1322
    void reserveNode(int n) { nodes.reserve(n); };
kpeter@736
  1323
kpeter@736
  1324
    /// Reserve memory for edges.
kpeter@736
  1325
kpeter@736
  1326
    /// Using this function, it is possible to avoid superfluous memory
kpeter@736
  1327
    /// allocation: if you know that the graph you want to build will
kpeter@736
  1328
    /// be large (e.g. it will contain millions of nodes and/or edges),
kpeter@736
  1329
    /// then it is worth reserving space for this amount before starting
kpeter@736
  1330
    /// to build the graph.
kpeter@736
  1331
    /// \sa reserveNode()
kpeter@736
  1332
    void reserveEdge(int m) { arcs.reserve(2 * m); };
kpeter@736
  1333
kpeter@73
  1334
    /// \brief Class to make a snapshot of the graph and restore
kpeter@73
  1335
    /// it later.
deba@57
  1336
    ///
kpeter@73
  1337
    /// Class to make a snapshot of the graph and restore it later.
deba@57
  1338
    ///
deba@57
  1339
    /// The newly added nodes and edges can be removed
deba@57
  1340
    /// using the restore() function.
deba@57
  1341
    ///
kpeter@735
  1342
    /// \note After a state is restored, you cannot restore a later state, 
kpeter@735
  1343
    /// i.e. you cannot add the removed nodes and edges again using
kpeter@735
  1344
    /// another Snapshot instance.
kpeter@735
  1345
    ///
kpeter@735
  1346
    /// \warning Node and edge deletions and other modifications
kpeter@735
  1347
    /// (e.g. changing the end-nodes of edges or contracting nodes)
kpeter@735
  1348
    /// cannot be restored. These events invalidate the snapshot.
kpeter@735
  1349
    /// However the edges and nodes that were added to the graph after
kpeter@735
  1350
    /// making the current snapshot can be removed without invalidating it.
deba@57
  1351
    class Snapshot {
deba@57
  1352
    protected:
deba@57
  1353
deba@57
  1354
      typedef Parent::NodeNotifier NodeNotifier;
deba@57
  1355
deba@57
  1356
      class NodeObserverProxy : public NodeNotifier::ObserverBase {
deba@57
  1357
      public:
deba@57
  1358
deba@57
  1359
        NodeObserverProxy(Snapshot& _snapshot)
deba@57
  1360
          : snapshot(_snapshot) {}
deba@57
  1361
deba@57
  1362
        using NodeNotifier::ObserverBase::attach;
deba@57
  1363
        using NodeNotifier::ObserverBase::detach;
deba@57
  1364
        using NodeNotifier::ObserverBase::attached;
alpar@209
  1365
deba@57
  1366
      protected:
alpar@209
  1367
deba@57
  1368
        virtual void add(const Node& node) {
deba@57
  1369
          snapshot.addNode(node);
deba@57
  1370
        }
deba@57
  1371
        virtual void add(const std::vector<Node>& nodes) {
deba@57
  1372
          for (int i = nodes.size() - 1; i >= 0; ++i) {
deba@57
  1373
            snapshot.addNode(nodes[i]);
deba@57
  1374
          }
deba@57
  1375
        }
deba@57
  1376
        virtual void erase(const Node& node) {
deba@57
  1377
          snapshot.eraseNode(node);
deba@57
  1378
        }
deba@57
  1379
        virtual void erase(const std::vector<Node>& nodes) {
deba@57
  1380
          for (int i = 0; i < int(nodes.size()); ++i) {
deba@57
  1381
            snapshot.eraseNode(nodes[i]);
deba@57
  1382
          }
deba@57
  1383
        }
deba@57
  1384
        virtual void build() {
deba@57
  1385
          Node node;
deba@57
  1386
          std::vector<Node> nodes;
alpar@209
  1387
          for (notifier()->first(node); node != INVALID;
deba@57
  1388
               notifier()->next(node)) {
deba@57
  1389
            nodes.push_back(node);
deba@57
  1390
          }
deba@57
  1391
          for (int i = nodes.size() - 1; i >= 0; --i) {
deba@57
  1392
            snapshot.addNode(nodes[i]);
deba@57
  1393
          }
deba@57
  1394
        }
deba@57
  1395
        virtual void clear() {
deba@57
  1396
          Node node;
alpar@209
  1397
          for (notifier()->first(node); node != INVALID;
deba@57
  1398
               notifier()->next(node)) {
deba@57
  1399
            snapshot.eraseNode(node);
deba@57
  1400
          }
deba@57
  1401
        }
deba@57
  1402
deba@57
  1403
        Snapshot& snapshot;
deba@57
  1404
      };
deba@57
  1405
deba@57
  1406
      class EdgeObserverProxy : public EdgeNotifier::ObserverBase {
deba@57
  1407
      public:
deba@57
  1408
deba@57
  1409
        EdgeObserverProxy(Snapshot& _snapshot)
deba@57
  1410
          : snapshot(_snapshot) {}
deba@57
  1411
deba@57
  1412
        using EdgeNotifier::ObserverBase::attach;
deba@57
  1413
        using EdgeNotifier::ObserverBase::detach;
deba@57
  1414
        using EdgeNotifier::ObserverBase::attached;
alpar@209
  1415
deba@57
  1416
      protected:
deba@57
  1417
kpeter@73
  1418
        virtual void add(const Edge& edge) {
kpeter@73
  1419
          snapshot.addEdge(edge);
deba@57
  1420
        }
kpeter@73
  1421
        virtual void add(const std::vector<Edge>& edges) {
kpeter@73
  1422
          for (int i = edges.size() - 1; i >= 0; ++i) {
kpeter@73
  1423
            snapshot.addEdge(edges[i]);
deba@57
  1424
          }
deba@57
  1425
        }
kpeter@73
  1426
        virtual void erase(const Edge& edge) {
kpeter@73
  1427
          snapshot.eraseEdge(edge);
deba@57
  1428
        }
kpeter@73
  1429
        virtual void erase(const std::vector<Edge>& edges) {
kpeter@73
  1430
          for (int i = 0; i < int(edges.size()); ++i) {
kpeter@73
  1431
            snapshot.eraseEdge(edges[i]);
deba@57
  1432
          }
deba@57
  1433
        }
deba@57
  1434
        virtual void build() {
kpeter@73
  1435
          Edge edge;
kpeter@73
  1436
          std::vector<Edge> edges;
alpar@209
  1437
          for (notifier()->first(edge); edge != INVALID;
kpeter@73
  1438
               notifier()->next(edge)) {
kpeter@73
  1439
            edges.push_back(edge);
deba@57
  1440
          }
kpeter@73
  1441
          for (int i = edges.size() - 1; i >= 0; --i) {
kpeter@73
  1442
            snapshot.addEdge(edges[i]);
deba@57
  1443
          }
deba@57
  1444
        }
deba@57
  1445
        virtual void clear() {
kpeter@73
  1446
          Edge edge;
alpar@209
  1447
          for (notifier()->first(edge); edge != INVALID;
kpeter@73
  1448
               notifier()->next(edge)) {
kpeter@73
  1449
            snapshot.eraseEdge(edge);
deba@57
  1450
          }
deba@57
  1451
        }
deba@57
  1452
deba@57
  1453
        Snapshot& snapshot;
deba@57
  1454
      };
kpeter@73
  1455
kpeter@73
  1456
      ListGraph *graph;
deba@57
  1457
deba@57
  1458
      NodeObserverProxy node_observer_proxy;
kpeter@73
  1459
      EdgeObserverProxy edge_observer_proxy;
deba@57
  1460
deba@57
  1461
      std::list<Node> added_nodes;
kpeter@73
  1462
      std::list<Edge> added_edges;
deba@57
  1463
deba@57
  1464
deba@57
  1465
      void addNode(const Node& node) {
alpar@209
  1466
        added_nodes.push_front(node);
deba@57
  1467
      }
deba@57
  1468
      void eraseNode(const Node& node) {
alpar@209
  1469
        std::list<Node>::iterator it =
deba@57
  1470
          std::find(added_nodes.begin(), added_nodes.end(), node);
deba@57
  1471
        if (it == added_nodes.end()) {
deba@57
  1472
          clear();
kpeter@73
  1473
          edge_observer_proxy.detach();
deba@57
  1474
          throw NodeNotifier::ImmediateDetach();
deba@57
  1475
        } else {
deba@57
  1476
          added_nodes.erase(it);
deba@57
  1477
        }
deba@57
  1478
      }
deba@57
  1479
kpeter@73
  1480
      void addEdge(const Edge& edge) {
alpar@209
  1481
        added_edges.push_front(edge);
deba@57
  1482
      }
kpeter@73
  1483
      void eraseEdge(const Edge& edge) {
alpar@209
  1484
        std::list<Edge>::iterator it =
kpeter@73
  1485
          std::find(added_edges.begin(), added_edges.end(), edge);
kpeter@73
  1486
        if (it == added_edges.end()) {
deba@57
  1487
          clear();
deba@57
  1488
          node_observer_proxy.detach();
deba@57
  1489
          throw EdgeNotifier::ImmediateDetach();
deba@57
  1490
        } else {
kpeter@73
  1491
          added_edges.erase(it);
kpeter@73
  1492
        }
deba@57
  1493
      }
deba@57
  1494
kpeter@73
  1495
      void attach(ListGraph &_graph) {
alpar@209
  1496
        graph = &_graph;
alpar@209
  1497
        node_observer_proxy.attach(graph->notifier(Node()));
kpeter@73
  1498
        edge_observer_proxy.attach(graph->notifier(Edge()));
deba@57
  1499
      }
alpar@209
  1500
deba@57
  1501
      void detach() {
alpar@209
  1502
        node_observer_proxy.detach();
alpar@209
  1503
        edge_observer_proxy.detach();
deba@57
  1504
      }
deba@57
  1505
deba@57
  1506
      bool attached() const {
deba@57
  1507
        return node_observer_proxy.attached();
deba@57
  1508
      }
deba@57
  1509
deba@57
  1510
      void clear() {
deba@57
  1511
        added_nodes.clear();
alpar@209
  1512
        added_edges.clear();
deba@57
  1513
      }
deba@57
  1514
deba@57
  1515
    public:
deba@57
  1516
deba@57
  1517
      /// \brief Default constructor.
deba@57
  1518
      ///
deba@57
  1519
      /// Default constructor.
kpeter@735
  1520
      /// You have to call save() to actually make a snapshot.
alpar@209
  1521
      Snapshot()
alpar@209
  1522
        : graph(0), node_observer_proxy(*this),
kpeter@73
  1523
          edge_observer_proxy(*this) {}
alpar@209
  1524
deba@57
  1525
      /// \brief Constructor that immediately makes a snapshot.
alpar@209
  1526
      ///
kpeter@735
  1527
      /// This constructor immediately makes a snapshot of the given graph.
kpeter@735
  1528
      Snapshot(ListGraph &gr)
alpar@209
  1529
        : node_observer_proxy(*this),
kpeter@73
  1530
          edge_observer_proxy(*this) {
kpeter@735
  1531
        attach(gr);
deba@57
  1532
      }
alpar@209
  1533
deba@57
  1534
      /// \brief Make a snapshot.
deba@57
  1535
      ///
kpeter@735
  1536
      /// This function makes a snapshot of the given graph.
kpeter@735
  1537
      /// It can be called more than once. In case of a repeated
deba@57
  1538
      /// call, the previous snapshot gets lost.
kpeter@735
  1539
      void save(ListGraph &gr) {
deba@57
  1540
        if (attached()) {
deba@57
  1541
          detach();
deba@57
  1542
          clear();
deba@57
  1543
        }
kpeter@735
  1544
        attach(gr);
deba@57
  1545
      }
alpar@209
  1546
deba@57
  1547
      /// \brief Undo the changes until the last snapshot.
kpeter@735
  1548
      ///
kpeter@735
  1549
      /// This function undos the changes until the last snapshot
kpeter@735
  1550
      /// created by save() or Snapshot(ListGraph&).
deba@57
  1551
      void restore() {
alpar@209
  1552
        detach();
alpar@209
  1553
        for(std::list<Edge>::iterator it = added_edges.begin();
kpeter@73
  1554
            it != added_edges.end(); ++it) {
alpar@209
  1555
          graph->erase(*it);
alpar@209
  1556
        }
alpar@209
  1557
        for(std::list<Node>::iterator it = added_nodes.begin();
deba@57
  1558
            it != added_nodes.end(); ++it) {
alpar@209
  1559
          graph->erase(*it);
alpar@209
  1560
        }
deba@57
  1561
        clear();
deba@57
  1562
      }
deba@57
  1563
kpeter@735
  1564
      /// \brief Returns \c true if the snapshot is valid.
deba@57
  1565
      ///
kpeter@735
  1566
      /// This function returns \c true if the snapshot is valid.
deba@57
  1567
      bool valid() const {
deba@57
  1568
        return attached();
deba@57
  1569
      }
deba@57
  1570
    };
deba@57
  1571
  };
alpar@209
  1572
alpar@209
  1573
  /// @}
deba@57
  1574
} //namespace lemon
alpar@209
  1575
deba@57
  1576
deba@57
  1577
#endif