lemon/list_graph.h
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 09 Oct 2008 22:41:29 +0200
changeset 318 1e2d6ca80793
parent 280 e7f8647ce760
child 341 d900fd1e760f
child 1078 c59bdcc8e33e
permissions -rw-r--r--
Doc improvements
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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) 2003-2008
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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, 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 simple and fast <em>directed graph</em>
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  ///implementation based on static linked lists that are stored in
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  ///\c std::vector structures.
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  ///
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  ///It conforms to the \ref concepts::Digraph "Digraph concept" and it
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  ///also provides several useful additional functionalities.
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  ///Most of the member functions and nested classes are documented
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  ///only in the concept class.
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  ///
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  ///An important extra feature of this digraph implementation is that
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  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
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  ///
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  ///\sa concepts::Digraph
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  class ListDigraph : public ExtendedListDigraphBase {
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  private:
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    ///ListDigraph is \e not copy constructible. Use copyDigraph() instead.
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    ///ListDigraph is \e not copy constructible. Use copyDigraph() instead.
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    ///
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    ListDigraph(const ListDigraph &) :ExtendedListDigraphBase() {};
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    ///\brief Assignment of ListDigraph to another one is \e not allowed.
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    ///Use copyDigraph() instead.
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    ///Assignment of ListDigraph to another one is \e not allowed.
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    ///Use copyDigraph() instead.
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    void operator=(const ListDigraph &) {}
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  public:
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    typedef ExtendedListDigraphBase Parent;
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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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    ///Add 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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    ///Add 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(const Node& s, const 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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    ///Erase a node from the digraph.
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    ///
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    void erase(const Node& n) { Parent::erase(n); }
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    ///\brief Erase an arc from the digraph.
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    ///
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    ///Erase an arc from the digraph.
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    ///
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    void erase(const Arc& a) { Parent::erase(a); }
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    /// Node validity check
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    /// This function gives back true if the given node is valid,
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    /// ie. it is a real node of the graph.
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    ///
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    /// \warning A Node pointing to a removed item
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    /// could become valid again later if new nodes are
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    /// added to the graph.
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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 true if the given arc is valid,
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    /// ie. it is a real arc of the graph.
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    ///
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    /// \warning An Arc pointing to a removed item
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    /// could become valid again later if new nodes are
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    /// added to the graph.
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    bool valid(Arc a) const { return Parent::valid(a); }
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    /// Change the target of \c a to \c n
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    /// Change the target of \c a to \c n
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    ///
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    ///\note The <tt>ArcIt</tt>s and <tt>OutArcIt</tt>s referencing
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    ///the changed arc remain valid. However <tt>InArcIt</tt>s are
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    ///invalidated.
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    ///
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   406
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   407
    ///feature.
deba@235
   408
    void changeTarget(Arc a, Node n) {
deba@235
   409
      Parent::changeTarget(a,n);
deba@57
   410
    }
deba@235
   411
    /// Change the source of \c a to \c n
deba@57
   412
deba@235
   413
    /// Change the source of \c a to \c n
deba@57
   414
    ///
deba@235
   415
    ///\note The <tt>InArcIt</tt>s referencing the changed arc remain
kpeter@313
   416
    ///valid. However the <tt>ArcIt</tt>s and <tt>OutArcIt</tt>s are
deba@57
   417
    ///invalidated.
kpeter@73
   418
    ///
deba@57
   419
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   420
    ///feature.
deba@235
   421
    void changeSource(Arc a, Node n) {
deba@235
   422
      Parent::changeSource(a,n);
deba@57
   423
    }
deba@57
   424
deba@57
   425
    /// Invert the direction of an arc.
deba@57
   426
deba@57
   427
    ///\note The <tt>ArcIt</tt>s referencing the changed arc remain
deba@57
   428
    ///valid. However <tt>OutArcIt</tt>s and <tt>InArcIt</tt>s are
deba@57
   429
    ///invalidated.
kpeter@73
   430
    ///
deba@57
   431
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   432
    ///feature.
deba@57
   433
    void reverseArc(Arc e) {
deba@57
   434
      Node t=target(e);
deba@57
   435
      changeTarget(e,source(e));
deba@57
   436
      changeSource(e,t);
deba@57
   437
    }
deba@57
   438
kpeter@73
   439
    /// Reserve memory for nodes.
kpeter@73
   440
kpeter@73
   441
    /// Using this function it is possible to avoid the superfluous memory
deba@57
   442
    /// allocation: if you know that the digraph you want to build will
deba@57
   443
    /// be very large (e.g. it will contain millions of nodes and/or arcs)
deba@57
   444
    /// then it is worth reserving space for this amount before starting
deba@57
   445
    /// to build the digraph.
deba@57
   446
    /// \sa reserveArc
deba@57
   447
    void reserveNode(int n) { nodes.reserve(n); };
deba@57
   448
kpeter@73
   449
    /// Reserve memory for arcs.
deba@57
   450
kpeter@73
   451
    /// Using this function it is possible to avoid the superfluous memory
deba@57
   452
    /// allocation: if you know that the digraph you want to build will
deba@57
   453
    /// be very large (e.g. it will contain millions of nodes and/or arcs)
deba@57
   454
    /// then it is worth reserving space for this amount before starting
deba@57
   455
    /// to build the digraph.
deba@57
   456
    /// \sa reserveNode
deba@57
   457
    void reserveArc(int m) { arcs.reserve(m); };
deba@57
   458
deba@57
   459
    ///Contract two nodes.
deba@57
   460
deba@57
   461
    ///This function contracts two nodes.
deba@57
   462
    ///Node \p b will be removed but instead of deleting
deba@57
   463
    ///incident arcs, they will be joined to \p a.
deba@57
   464
    ///The last parameter \p r controls whether to remove loops. \c true
deba@57
   465
    ///means that loops will be removed.
deba@57
   466
    ///
kpeter@73
   467
    ///\note The <tt>ArcIt</tt>s referencing a moved arc remain
deba@57
   468
    ///valid. However <tt>InArcIt</tt>s and <tt>OutArcIt</tt>s
deba@57
   469
    ///may be invalidated.
kpeter@73
   470
    ///
deba@57
   471
    ///\warning This functionality cannot be used together with the Snapshot
deba@57
   472
    ///feature.
alpar@209
   473
    void contract(Node a, Node b, bool r = true)
deba@57
   474
    {
deba@57
   475
      for(OutArcIt e(*this,b);e!=INVALID;) {
alpar@209
   476
        OutArcIt f=e;
alpar@209
   477
        ++f;
alpar@209
   478
        if(r && target(e)==a) erase(e);
alpar@209
   479
        else changeSource(e,a);
alpar@209
   480
        e=f;
deba@57
   481
      }
deba@57
   482
      for(InArcIt e(*this,b);e!=INVALID;) {
alpar@209
   483
        InArcIt f=e;
alpar@209
   484
        ++f;
alpar@209
   485
        if(r && source(e)==a) erase(e);
alpar@209
   486
        else changeTarget(e,a);
alpar@209
   487
        e=f;
deba@57
   488
      }
deba@57
   489
      erase(b);
deba@57
   490
    }
deba@57
   491
deba@57
   492
    ///Split a node.
deba@57
   493
deba@57
   494
    ///This function splits a node. First a new node is added to the digraph,
deba@57
   495
    ///then the source of each outgoing arc of \c n is moved to this new node.
deba@57
   496
    ///If \c connect is \c true (this is the default value), then a new arc
deba@57
   497
    ///from \c n to the newly created node is also added.
deba@57
   498
    ///\return The newly created node.
deba@57
   499
    ///
deba@57
   500
    ///\note The <tt>ArcIt</tt>s referencing a moved arc remain
deba@57
   501
    ///valid. However <tt>InArcIt</tt>s and <tt>OutArcIt</tt>s may
alpar@209
   502
    ///be invalidated.
deba@57
   503
    ///
alpar@280
   504
    ///\warning This functionality cannot be used in conjunction with the
kpeter@73
   505
    ///Snapshot feature.
deba@57
   506
    Node split(Node n, bool connect = true) {
deba@57
   507
      Node b = addNode();
deba@57
   508
      for(OutArcIt e(*this,n);e!=INVALID;) {
kpeter@212
   509
        OutArcIt f=e;
alpar@209
   510
        ++f;
alpar@209
   511
        changeSource(e,b);
alpar@209
   512
        e=f;
deba@57
   513
      }
deba@57
   514
      if (connect) addArc(n,b);
deba@57
   515
      return b;
deba@57
   516
    }
alpar@209
   517
deba@57
   518
    ///Split an arc.
deba@57
   519
deba@57
   520
    ///This function splits an arc. First a new node \c b is added to
deba@57
   521
    ///the digraph, then the original arc is re-targeted to \c
deba@57
   522
    ///b. Finally an arc from \c b to the original target is added.
kpeter@73
   523
    ///
kpeter@73
   524
    ///\return The newly created node.
kpeter@73
   525
    ///
kpeter@73
   526
    ///\warning This functionality cannot be used together with the
kpeter@73
   527
    ///Snapshot feature.
deba@57
   528
    Node split(Arc e) {
deba@57
   529
      Node b = addNode();
deba@57
   530
      addArc(b,target(e));
deba@57
   531
      changeTarget(e,b);
deba@57
   532
      return b;
deba@57
   533
    }
alpar@209
   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@73
   543
    /// \warning Arc and node deletions and other modifications (e.g.
alpar@209
   544
    /// contracting, splitting, reversing arcs or nodes) cannot be
alpar@209
   545
    /// restored. These events invalidate the snapshot.
deba@57
   546
    class Snapshot {
deba@57
   547
    protected:
deba@57
   548
deba@57
   549
      typedef Parent::NodeNotifier NodeNotifier;
deba@57
   550
deba@57
   551
      class NodeObserverProxy : public NodeNotifier::ObserverBase {
deba@57
   552
      public:
deba@57
   553
deba@57
   554
        NodeObserverProxy(Snapshot& _snapshot)
deba@57
   555
          : snapshot(_snapshot) {}
deba@57
   556
deba@57
   557
        using NodeNotifier::ObserverBase::attach;
deba@57
   558
        using NodeNotifier::ObserverBase::detach;
deba@57
   559
        using NodeNotifier::ObserverBase::attached;
alpar@209
   560
deba@57
   561
      protected:
alpar@209
   562
deba@57
   563
        virtual void add(const Node& node) {
deba@57
   564
          snapshot.addNode(node);
deba@57
   565
        }
deba@57
   566
        virtual void add(const std::vector<Node>& nodes) {
deba@57
   567
          for (int i = nodes.size() - 1; i >= 0; ++i) {
deba@57
   568
            snapshot.addNode(nodes[i]);
deba@57
   569
          }
deba@57
   570
        }
deba@57
   571
        virtual void erase(const Node& node) {
deba@57
   572
          snapshot.eraseNode(node);
deba@57
   573
        }
deba@57
   574
        virtual void erase(const std::vector<Node>& nodes) {
deba@57
   575
          for (int i = 0; i < int(nodes.size()); ++i) {
deba@57
   576
            snapshot.eraseNode(nodes[i]);
deba@57
   577
          }
deba@57
   578
        }
deba@57
   579
        virtual void build() {
deba@57
   580
          Node node;
deba@57
   581
          std::vector<Node> nodes;
alpar@209
   582
          for (notifier()->first(node); node != INVALID;
deba@57
   583
               notifier()->next(node)) {
deba@57
   584
            nodes.push_back(node);
deba@57
   585
          }
deba@57
   586
          for (int i = nodes.size() - 1; i >= 0; --i) {
deba@57
   587
            snapshot.addNode(nodes[i]);
deba@57
   588
          }
deba@57
   589
        }
deba@57
   590
        virtual void clear() {
deba@57
   591
          Node node;
alpar@209
   592
          for (notifier()->first(node); node != INVALID;
deba@57
   593
               notifier()->next(node)) {
deba@57
   594
            snapshot.eraseNode(node);
deba@57
   595
          }
deba@57
   596
        }
deba@57
   597
deba@57
   598
        Snapshot& snapshot;
deba@57
   599
      };
deba@57
   600
deba@57
   601
      class ArcObserverProxy : public ArcNotifier::ObserverBase {
deba@57
   602
      public:
deba@57
   603
deba@57
   604
        ArcObserverProxy(Snapshot& _snapshot)
deba@57
   605
          : snapshot(_snapshot) {}
deba@57
   606
deba@57
   607
        using ArcNotifier::ObserverBase::attach;
deba@57
   608
        using ArcNotifier::ObserverBase::detach;
deba@57
   609
        using ArcNotifier::ObserverBase::attached;
alpar@209
   610
deba@57
   611
      protected:
deba@57
   612
deba@57
   613
        virtual void add(const Arc& arc) {
deba@57
   614
          snapshot.addArc(arc);
deba@57
   615
        }
deba@57
   616
        virtual void add(const std::vector<Arc>& arcs) {
deba@57
   617
          for (int i = arcs.size() - 1; i >= 0; ++i) {
deba@57
   618
            snapshot.addArc(arcs[i]);
deba@57
   619
          }
deba@57
   620
        }
deba@57
   621
        virtual void erase(const Arc& arc) {
deba@57
   622
          snapshot.eraseArc(arc);
deba@57
   623
        }
deba@57
   624
        virtual void erase(const std::vector<Arc>& arcs) {
deba@57
   625
          for (int i = 0; i < int(arcs.size()); ++i) {
deba@57
   626
            snapshot.eraseArc(arcs[i]);
deba@57
   627
          }
deba@57
   628
        }
deba@57
   629
        virtual void build() {
deba@57
   630
          Arc arc;
deba@57
   631
          std::vector<Arc> arcs;
alpar@209
   632
          for (notifier()->first(arc); arc != INVALID;
deba@57
   633
               notifier()->next(arc)) {
deba@57
   634
            arcs.push_back(arc);
deba@57
   635
          }
deba@57
   636
          for (int i = arcs.size() - 1; i >= 0; --i) {
deba@57
   637
            snapshot.addArc(arcs[i]);
deba@57
   638
          }
deba@57
   639
        }
deba@57
   640
        virtual void clear() {
deba@57
   641
          Arc arc;
alpar@209
   642
          for (notifier()->first(arc); arc != INVALID;
deba@57
   643
               notifier()->next(arc)) {
deba@57
   644
            snapshot.eraseArc(arc);
deba@57
   645
          }
deba@57
   646
        }
deba@57
   647
deba@57
   648
        Snapshot& snapshot;
deba@57
   649
      };
alpar@209
   650
deba@57
   651
      ListDigraph *digraph;
deba@57
   652
deba@57
   653
      NodeObserverProxy node_observer_proxy;
deba@57
   654
      ArcObserverProxy arc_observer_proxy;
deba@57
   655
deba@57
   656
      std::list<Node> added_nodes;
deba@57
   657
      std::list<Arc> added_arcs;
deba@57
   658
deba@57
   659
deba@57
   660
      void addNode(const Node& node) {
alpar@209
   661
        added_nodes.push_front(node);
deba@57
   662
      }
deba@57
   663
      void eraseNode(const Node& node) {
alpar@209
   664
        std::list<Node>::iterator it =
deba@57
   665
          std::find(added_nodes.begin(), added_nodes.end(), node);
deba@57
   666
        if (it == added_nodes.end()) {
deba@57
   667
          clear();
deba@57
   668
          arc_observer_proxy.detach();
deba@57
   669
          throw NodeNotifier::ImmediateDetach();
deba@57
   670
        } else {
deba@57
   671
          added_nodes.erase(it);
deba@57
   672
        }
deba@57
   673
      }
deba@57
   674
deba@57
   675
      void addArc(const Arc& arc) {
alpar@209
   676
        added_arcs.push_front(arc);
deba@57
   677
      }
deba@57
   678
      void eraseArc(const Arc& arc) {
alpar@209
   679
        std::list<Arc>::iterator it =
deba@57
   680
          std::find(added_arcs.begin(), added_arcs.end(), arc);
deba@57
   681
        if (it == added_arcs.end()) {
deba@57
   682
          clear();
alpar@209
   683
          node_observer_proxy.detach();
deba@57
   684
          throw ArcNotifier::ImmediateDetach();
deba@57
   685
        } else {
deba@57
   686
          added_arcs.erase(it);
alpar@209
   687
        }
deba@57
   688
      }
deba@57
   689
deba@57
   690
      void attach(ListDigraph &_digraph) {
alpar@209
   691
        digraph = &_digraph;
alpar@209
   692
        node_observer_proxy.attach(digraph->notifier(Node()));
deba@57
   693
        arc_observer_proxy.attach(digraph->notifier(Arc()));
deba@57
   694
      }
alpar@209
   695
deba@57
   696
      void detach() {
alpar@209
   697
        node_observer_proxy.detach();
alpar@209
   698
        arc_observer_proxy.detach();
deba@57
   699
      }
deba@57
   700
deba@57
   701
      bool attached() const {
deba@57
   702
        return node_observer_proxy.attached();
deba@57
   703
      }
deba@57
   704
deba@57
   705
      void clear() {
deba@57
   706
        added_nodes.clear();
alpar@209
   707
        added_arcs.clear();
deba@57
   708
      }
deba@57
   709
deba@57
   710
    public:
deba@57
   711
deba@57
   712
      /// \brief Default constructor.
deba@57
   713
      ///
deba@57
   714
      /// Default constructor.
deba@57
   715
      /// To actually make a snapshot you must call save().
alpar@209
   716
      Snapshot()
alpar@209
   717
        : digraph(0), node_observer_proxy(*this),
deba@57
   718
          arc_observer_proxy(*this) {}
alpar@209
   719
deba@57
   720
      /// \brief Constructor that immediately makes a snapshot.
alpar@209
   721
      ///
deba@57
   722
      /// This constructor immediately makes a snapshot of the digraph.
deba@57
   723
      /// \param _digraph The digraph we make a snapshot of.
alpar@209
   724
      Snapshot(ListDigraph &_digraph)
alpar@209
   725
        : node_observer_proxy(*this),
deba@57
   726
          arc_observer_proxy(*this) {
alpar@209
   727
        attach(_digraph);
deba@57
   728
      }
alpar@209
   729
deba@57
   730
      /// \brief Make a snapshot.
deba@57
   731
      ///
deba@57
   732
      /// Make a snapshot of the digraph.
deba@57
   733
      ///
deba@57
   734
      /// This function can be called more than once. In case of a repeated
deba@57
   735
      /// call, the previous snapshot gets lost.
deba@57
   736
      /// \param _digraph The digraph we make the snapshot of.
deba@57
   737
      void save(ListDigraph &_digraph) {
deba@57
   738
        if (attached()) {
deba@57
   739
          detach();
deba@57
   740
          clear();
deba@57
   741
        }
deba@57
   742
        attach(_digraph);
deba@57
   743
      }
alpar@209
   744
deba@57
   745
      /// \brief Undo the changes until the last snapshot.
alpar@209
   746
      //
deba@57
   747
      /// Undo the changes until the last snapshot created by save().
deba@57
   748
      void restore() {
alpar@209
   749
        detach();
alpar@209
   750
        for(std::list<Arc>::iterator it = added_arcs.begin();
deba@57
   751
            it != added_arcs.end(); ++it) {
alpar@209
   752
          digraph->erase(*it);
alpar@209
   753
        }
alpar@209
   754
        for(std::list<Node>::iterator it = added_nodes.begin();
deba@57
   755
            it != added_nodes.end(); ++it) {
alpar@209
   756
          digraph->erase(*it);
alpar@209
   757
        }
deba@57
   758
        clear();
deba@57
   759
      }
deba@57
   760
deba@57
   761
      /// \brief Gives back true when the snapshot is valid.
deba@57
   762
      ///
deba@57
   763
      /// Gives back true when the snapshot is valid.
deba@57
   764
      bool valid() const {
deba@57
   765
        return attached();
deba@57
   766
      }
deba@57
   767
    };
alpar@209
   768
deba@57
   769
  };
deba@57
   770
deba@57
   771
  ///@}
deba@57
   772
deba@57
   773
  class ListGraphBase {
deba@57
   774
deba@57
   775
  protected:
deba@57
   776
deba@57
   777
    struct NodeT {
deba@57
   778
      int first_out;
deba@57
   779
      int prev, next;
deba@57
   780
    };
alpar@209
   781
deba@57
   782
    struct ArcT {
deba@57
   783
      int target;
deba@57
   784
      int prev_out, next_out;
deba@57
   785
    };
deba@57
   786
deba@57
   787
    std::vector<NodeT> nodes;
deba@57
   788
deba@57
   789
    int first_node;
deba@57
   790
deba@57
   791
    int first_free_node;
deba@57
   792
deba@57
   793
    std::vector<ArcT> arcs;
deba@57
   794
deba@57
   795
    int first_free_arc;
alpar@209
   796
deba@57
   797
  public:
alpar@209
   798
deba@57
   799
    typedef ListGraphBase Digraph;
deba@57
   800
deba@57
   801
    class Node;
deba@57
   802
    class Arc;
deba@57
   803
    class Edge;
alpar@209
   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:
deba@238
   843
      operator Edge() const { 
deba@238
   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
deba@57
   855
deba@57
   856
    ListGraphBase()
deba@57
   857
      : nodes(), first_node(-1),
alpar@209
   858
        first_free_node(-1), arcs(), first_free_arc(-1) {}
deba@57
   859
alpar@209
   860
alpar@209
   861
    int maxNodeId() const { return nodes.size()-1; }
deba@57
   862
    int maxEdgeId() const { return arcs.size() / 2 - 1; }
deba@57
   863
    int maxArcId() const { return arcs.size()-1; }
deba@57
   864
deba@57
   865
    Node source(Arc e) const { return Node(arcs[e.id ^ 1].target); }
deba@57
   866
    Node target(Arc e) const { return Node(arcs[e.id].target); }
deba@57
   867
deba@57
   868
    Node u(Edge e) const { return Node(arcs[2 * e.id].target); }
deba@57
   869
    Node v(Edge e) const { return Node(arcs[2 * e.id + 1].target); }
deba@57
   870
deba@57
   871
    static bool direction(Arc e) {
deba@57
   872
      return (e.id & 1) == 1;
deba@57
   873
    }
deba@57
   874
deba@57
   875
    static Arc direct(Edge e, bool d) {
deba@57
   876
      return Arc(e.id * 2 + (d ? 1 : 0));
deba@57
   877
    }
deba@57
   878
alpar@209
   879
    void first(Node& node) const {
deba@57
   880
      node.id = first_node;
deba@57
   881
    }
deba@57
   882
deba@57
   883
    void next(Node& node) const {
deba@57
   884
      node.id = nodes[node.id].next;
deba@57
   885
    }
deba@57
   886
alpar@209
   887
    void first(Arc& e) const {
deba@57
   888
      int n = first_node;
deba@57
   889
      while (n != -1 && nodes[n].first_out == -1) {
deba@57
   890
        n = nodes[n].next;
deba@57
   891
      }
deba@57
   892
      e.id = (n == -1) ? -1 : nodes[n].first_out;
deba@57
   893
    }
deba@57
   894
deba@57
   895
    void next(Arc& e) const {
deba@57
   896
      if (arcs[e.id].next_out != -1) {
alpar@209
   897
        e.id = arcs[e.id].next_out;
deba@57
   898
      } else {
alpar@209
   899
        int n = nodes[arcs[e.id ^ 1].target].next;
deba@57
   900
        while(n != -1 && nodes[n].first_out == -1) {
deba@57
   901
          n = nodes[n].next;
deba@57
   902
        }
alpar@209
   903
        e.id = (n == -1) ? -1 : nodes[n].first_out;
alpar@209
   904
      }
deba@57
   905
    }
deba@57
   906
alpar@209
   907
    void first(Edge& e) const {
deba@57
   908
      int n = first_node;
deba@57
   909
      while (n != -1) {
deba@57
   910
        e.id = nodes[n].first_out;
deba@57
   911
        while ((e.id & 1) != 1) {
deba@57
   912
          e.id = arcs[e.id].next_out;
deba@57
   913
        }
deba@57
   914
        if (e.id != -1) {
deba@57
   915
          e.id /= 2;
deba@57
   916
          return;
alpar@209
   917
        }
deba@57
   918
        n = nodes[n].next;
deba@57
   919
      }
deba@57
   920
      e.id = -1;
deba@57
   921
    }
deba@57
   922
deba@57
   923
    void next(Edge& e) const {
deba@57
   924
      int n = arcs[e.id * 2].target;
deba@57
   925
      e.id = arcs[(e.id * 2) | 1].next_out;
deba@57
   926
      while ((e.id & 1) != 1) {
deba@57
   927
        e.id = arcs[e.id].next_out;
deba@57
   928
      }
deba@57
   929
      if (e.id != -1) {
deba@57
   930
        e.id /= 2;
deba@57
   931
        return;
alpar@209
   932
      }
deba@57
   933
      n = nodes[n].next;
deba@57
   934
      while (n != -1) {
deba@57
   935
        e.id = nodes[n].first_out;
deba@57
   936
        while ((e.id & 1) != 1) {
deba@57
   937
          e.id = arcs[e.id].next_out;
deba@57
   938
        }
deba@57
   939
        if (e.id != -1) {
deba@57
   940
          e.id /= 2;
deba@57
   941
          return;
alpar@209
   942
        }
deba@57
   943
        n = nodes[n].next;
deba@57
   944
      }
deba@57
   945
      e.id = -1;
deba@57
   946
    }
deba@57
   947
deba@57
   948
    void firstOut(Arc &e, const Node& v) const {
deba@57
   949
      e.id = nodes[v.id].first_out;
deba@57
   950
    }
deba@57
   951
    void nextOut(Arc &e) const {
deba@57
   952
      e.id = arcs[e.id].next_out;
deba@57
   953
    }
deba@57
   954
deba@57
   955
    void firstIn(Arc &e, const Node& v) const {
deba@57
   956
      e.id = ((nodes[v.id].first_out) ^ 1);
deba@57
   957
      if (e.id == -2) e.id = -1;
deba@57
   958
    }
deba@57
   959
    void nextIn(Arc &e) const {
deba@57
   960
      e.id = ((arcs[e.id ^ 1].next_out) ^ 1);
deba@57
   961
      if (e.id == -2) e.id = -1;
deba@57
   962
    }
deba@57
   963
deba@57
   964
    void firstInc(Edge &e, bool& d, const Node& v) const {
kpeter@73
   965
      int a = nodes[v.id].first_out;
kpeter@73
   966
      if (a != -1 ) {
kpeter@73
   967
        e.id = a / 2;
kpeter@73
   968
        d = ((a & 1) == 1);
deba@57
   969
      } else {
deba@57
   970
        e.id = -1;
deba@57
   971
        d = true;
deba@57
   972
      }
deba@57
   973
    }
deba@57
   974
    void nextInc(Edge &e, bool& d) const {
kpeter@73
   975
      int a = (arcs[(e.id * 2) | (d ? 1 : 0)].next_out);
kpeter@73
   976
      if (a != -1 ) {
kpeter@73
   977
        e.id = a / 2;
kpeter@73
   978
        d = ((a & 1) == 1);
deba@57
   979
      } else {
deba@57
   980
        e.id = -1;
deba@57
   981
        d = true;
deba@57
   982
      }
deba@57
   983
    }
alpar@209
   984
deba@57
   985
    static int id(Node v) { return v.id; }
deba@57
   986
    static int id(Arc e) { return e.id; }
deba@57
   987
    static int id(Edge e) { return e.id; }
deba@57
   988
deba@57
   989
    static Node nodeFromId(int id) { return Node(id);}
deba@57
   990
    static Arc arcFromId(int id) { return Arc(id);}
deba@57
   991
    static Edge edgeFromId(int id) { return Edge(id);}
deba@57
   992
alpar@209
   993
    bool valid(Node n) const {
alpar@209
   994
      return n.id >= 0 && n.id < static_cast<int>(nodes.size()) &&
alpar@209
   995
        nodes[n.id].prev != -2;
deba@149
   996
    }
deba@149
   997
alpar@209
   998
    bool valid(Arc a) const {
alpar@209
   999
      return a.id >= 0 && a.id < static_cast<int>(arcs.size()) &&
alpar@209
  1000
        arcs[a.id].prev_out != -2;
deba@149
  1001
    }
deba@149
  1002
alpar@209
  1003
    bool valid(Edge e) const {
alpar@209
  1004
      return e.id >= 0 && 2 * e.id < static_cast<int>(arcs.size()) &&
alpar@209
  1005
        arcs[2 * e.id].prev_out != -2;
deba@149
  1006
    }
deba@149
  1007
alpar@209
  1008
    Node addNode() {
deba@57
  1009
      int n;
alpar@209
  1010
deba@57
  1011
      if(first_free_node==-1) {
alpar@209
  1012
        n = nodes.size();
alpar@209
  1013
        nodes.push_back(NodeT());
deba@57
  1014
      } else {
alpar@209
  1015
        n = first_free_node;
alpar@209
  1016
        first_free_node = nodes[n].next;
deba@57
  1017
      }
alpar@209
  1018
deba@57
  1019
      nodes[n].next = first_node;
deba@57
  1020
      if (first_node != -1) nodes[first_node].prev = n;
deba@57
  1021
      first_node = n;
deba@57
  1022
      nodes[n].prev = -1;
alpar@209
  1023
deba@57
  1024
      nodes[n].first_out = -1;
alpar@209
  1025
deba@57
  1026
      return Node(n);
deba@57
  1027
    }
alpar@209
  1028
deba@57
  1029
    Edge addEdge(Node u, Node v) {
alpar@209
  1030
      int n;
deba@57
  1031
deba@57
  1032
      if (first_free_arc == -1) {
alpar@209
  1033
        n = arcs.size();
alpar@209
  1034
        arcs.push_back(ArcT());
alpar@209
  1035
        arcs.push_back(ArcT());
deba@57
  1036
      } else {
alpar@209
  1037
        n = first_free_arc;
alpar@209
  1038
        first_free_arc = arcs[n].next_out;
deba@57
  1039
      }
alpar@209
  1040
deba@57
  1041
      arcs[n].target = u.id;
deba@57
  1042
      arcs[n | 1].target = v.id;
deba@57
  1043
deba@57
  1044
      arcs[n].next_out = nodes[v.id].first_out;
deba@57
  1045
      if (nodes[v.id].first_out != -1) {
alpar@209
  1046
        arcs[nodes[v.id].first_out].prev_out = n;
alpar@209
  1047
      }
deba@57
  1048
      arcs[n].prev_out = -1;
deba@57
  1049
      nodes[v.id].first_out = n;
alpar@209
  1050
deba@57
  1051
      arcs[n | 1].next_out = nodes[u.id].first_out;
deba@57
  1052
      if (nodes[u.id].first_out != -1) {
alpar@209
  1053
        arcs[nodes[u.id].first_out].prev_out = (n | 1);
deba@57
  1054
      }
alpar@209
  1055
      arcs[n | 1].prev_out = -1;
deba@57
  1056
      nodes[u.id].first_out = (n | 1);
deba@57
  1057
deba@57
  1058
      return Edge(n / 2);
deba@57
  1059
    }
alpar@209
  1060
deba@57
  1061
    void erase(const Node& node) {
deba@57
  1062
      int n = node.id;
alpar@209
  1063
deba@57
  1064
      if(nodes[n].next != -1) {
alpar@209
  1065
        nodes[nodes[n].next].prev = nodes[n].prev;
deba@57
  1066
      }
alpar@209
  1067
deba@57
  1068
      if(nodes[n].prev != -1) {
alpar@209
  1069
        nodes[nodes[n].prev].next = nodes[n].next;
deba@57
  1070
      } else {
alpar@209
  1071
        first_node = nodes[n].next;
deba@57
  1072
      }
alpar@209
  1073
deba@57
  1074
      nodes[n].next = first_free_node;
deba@57
  1075
      first_free_node = n;
deba@149
  1076
      nodes[n].prev = -2;
deba@57
  1077
    }
alpar@209
  1078
kpeter@73
  1079
    void erase(const Edge& edge) {
kpeter@73
  1080
      int n = edge.id * 2;
alpar@209
  1081
deba@57
  1082
      if (arcs[n].next_out != -1) {
alpar@209
  1083
        arcs[arcs[n].next_out].prev_out = arcs[n].prev_out;
alpar@209
  1084
      }
deba@57
  1085
deba@57
  1086
      if (arcs[n].prev_out != -1) {
alpar@209
  1087
        arcs[arcs[n].prev_out].next_out = arcs[n].next_out;
deba@57
  1088
      } else {
alpar@209
  1089
        nodes[arcs[n | 1].target].first_out = arcs[n].next_out;
deba@57
  1090
      }
deba@57
  1091
deba@57
  1092
      if (arcs[n | 1].next_out != -1) {
alpar@209
  1093
        arcs[arcs[n | 1].next_out].prev_out = arcs[n | 1].prev_out;
alpar@209
  1094
      }
deba@57
  1095
deba@57
  1096
      if (arcs[n | 1].prev_out != -1) {
alpar@209
  1097
        arcs[arcs[n | 1].prev_out].next_out = arcs[n | 1].next_out;
deba@57
  1098
      } else {
alpar@209
  1099
        nodes[arcs[n].target].first_out = arcs[n | 1].next_out;
deba@57
  1100
      }
alpar@209
  1101
deba@57
  1102
      arcs[n].next_out = first_free_arc;
alpar@209
  1103
      first_free_arc = n;
deba@149
  1104
      arcs[n].prev_out = -2;
deba@149
  1105
      arcs[n | 1].prev_out = -2;
deba@57
  1106
deba@57
  1107
    }
deba@57
  1108
deba@57
  1109
    void clear() {
deba@57
  1110
      arcs.clear();
deba@57
  1111
      nodes.clear();
deba@57
  1112
      first_node = first_free_node = first_free_arc = -1;
deba@57
  1113
    }
deba@57
  1114
deba@57
  1115
  protected:
deba@57
  1116
deba@235
  1117
    void changeV(Edge e, Node n) {
deba@57
  1118
      if(arcs[2 * e.id].next_out != -1) {
alpar@209
  1119
        arcs[arcs[2 * e.id].next_out].prev_out = arcs[2 * e.id].prev_out;
deba@57
  1120
      }
deba@57
  1121
      if(arcs[2 * e.id].prev_out != -1) {
alpar@209
  1122
        arcs[arcs[2 * e.id].prev_out].next_out =
deba@57
  1123
          arcs[2 * e.id].next_out;
deba@57
  1124
      } else {
alpar@209
  1125
        nodes[arcs[(2 * e.id) | 1].target].first_out =
deba@57
  1126
          arcs[2 * e.id].next_out;
deba@57
  1127
      }
deba@57
  1128
deba@57
  1129
      if (nodes[n.id].first_out != -1) {
alpar@209
  1130
        arcs[nodes[n.id].first_out].prev_out = 2 * e.id;
deba@57
  1131
      }
deba@57
  1132
      arcs[(2 * e.id) | 1].target = n.id;
deba@57
  1133
      arcs[2 * e.id].prev_out = -1;
deba@57
  1134
      arcs[2 * e.id].next_out = nodes[n.id].first_out;
deba@57
  1135
      nodes[n.id].first_out = 2 * e.id;
deba@57
  1136
    }
deba@57
  1137
deba@235
  1138
    void changeU(Edge e, Node n) {
deba@57
  1139
      if(arcs[(2 * e.id) | 1].next_out != -1) {
alpar@209
  1140
        arcs[arcs[(2 * e.id) | 1].next_out].prev_out =
deba@57
  1141
          arcs[(2 * e.id) | 1].prev_out;
deba@57
  1142
      }
deba@57
  1143
      if(arcs[(2 * e.id) | 1].prev_out != -1) {
alpar@209
  1144
        arcs[arcs[(2 * e.id) | 1].prev_out].next_out =
deba@57
  1145
          arcs[(2 * e.id) | 1].next_out;
deba@57
  1146
      } else {
alpar@209
  1147
        nodes[arcs[2 * e.id].target].first_out =
deba@57
  1148
          arcs[(2 * e.id) | 1].next_out;
deba@57
  1149
      }
deba@57
  1150
deba@57
  1151
      if (nodes[n.id].first_out != -1) {
alpar@209
  1152
        arcs[nodes[n.id].first_out].prev_out = ((2 * e.id) | 1);
deba@57
  1153
      }
deba@57
  1154
      arcs[2 * e.id].target = n.id;
deba@57
  1155
      arcs[(2 * e.id) | 1].prev_out = -1;
deba@57
  1156
      arcs[(2 * e.id) | 1].next_out = nodes[n.id].first_out;
deba@57
  1157
      nodes[n.id].first_out = ((2 * e.id) | 1);
deba@57
  1158
    }
deba@57
  1159
deba@57
  1160
  };
deba@57
  1161
deba@57
  1162
  typedef GraphExtender<ListGraphBase> ExtendedListGraphBase;
deba@57
  1163
deba@57
  1164
kpeter@73
  1165
  /// \addtogroup graphs
deba@57
  1166
  /// @{
deba@57
  1167
kpeter@73
  1168
  ///A general undirected graph structure.
deba@57
  1169
alpar@209
  1170
  ///\ref ListGraph is a simple and fast <em>undirected graph</em>
alpar@209
  1171
  ///implementation based on static linked lists that are stored in
alpar@209
  1172
  ///\c std::vector structures.
deba@57
  1173
  ///
kpeter@73
  1174
  ///It conforms to the \ref concepts::Graph "Graph concept" and it
kpeter@73
  1175
  ///also provides several useful additional functionalities.
kpeter@73
  1176
  ///Most of the member functions and nested classes are documented
kpeter@73
  1177
  ///only in the concept class.
kpeter@73
  1178
  ///
kpeter@73
  1179
  ///An important extra feature of this graph implementation is that
deba@57
  1180
  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
deba@57
  1181
  ///
kpeter@73
  1182
  ///\sa concepts::Graph
kpeter@73
  1183
deba@57
  1184
  class ListGraph : public ExtendedListGraphBase {
deba@57
  1185
  private:
kpeter@73
  1186
    ///ListGraph is \e not copy constructible. Use copyGraph() instead.
deba@57
  1187
kpeter@73
  1188
    ///ListGraph is \e not copy constructible. Use copyGraph() instead.
deba@57
  1189
    ///
deba@57
  1190
    ListGraph(const ListGraph &) :ExtendedListGraphBase()  {};
deba@57
  1191
    ///\brief Assignment of ListGraph to another one is \e not allowed.
kpeter@73
  1192
    ///Use copyGraph() instead.
deba@57
  1193
deba@57
  1194
    ///Assignment of ListGraph to another one is \e not allowed.
kpeter@73
  1195
    ///Use copyGraph() instead.
deba@57
  1196
    void operator=(const ListGraph &) {}
deba@57
  1197
  public:
deba@57
  1198
    /// Constructor
alpar@209
  1199
deba@57
  1200
    /// Constructor.
deba@57
  1201
    ///
deba@57
  1202
    ListGraph() {}
deba@57
  1203
deba@57
  1204
    typedef ExtendedListGraphBase Parent;
deba@57
  1205
kpeter@73
  1206
    typedef Parent::OutArcIt IncEdgeIt;
deba@57
  1207
kpeter@73
  1208
    /// \brief Add a new node to the graph.
deba@57
  1209
    ///
kpeter@73
  1210
    /// Add a new node to the graph.
deba@57
  1211
    /// \return the new node.
deba@57
  1212
    Node addNode() { return Parent::addNode(); }
deba@57
  1213
kpeter@73
  1214
    /// \brief Add a new edge to the graph.
deba@57
  1215
    ///
kpeter@73
  1216
    /// Add a new edge to the graph with source node \c s
deba@57
  1217
    /// and target node \c t.
deba@57
  1218
    /// \return the new edge.
alpar@209
  1219
    Edge addEdge(const Node& s, const Node& t) {
alpar@209
  1220
      return Parent::addEdge(s, t);
deba@57
  1221
    }
deba@234
  1222
deba@234
  1223
    /// \brief Erase a node from the graph.
deba@234
  1224
    ///
deba@234
  1225
    /// Erase a node from the graph.
deba@234
  1226
    ///
deba@234
  1227
    void erase(const Node& n) { Parent::erase(n); }
deba@234
  1228
deba@234
  1229
    /// \brief Erase an edge from the graph.
deba@234
  1230
    ///
deba@234
  1231
    /// Erase an edge from the graph.
deba@234
  1232
    ///
deba@234
  1233
    void erase(const Edge& e) { Parent::erase(e); }
deba@149
  1234
    /// Node validity check
deba@149
  1235
deba@149
  1236
    /// This function gives back true if the given node is valid,
alpar@209
  1237
    /// ie. it is a real node of the graph.
deba@149
  1238
    ///
deba@149
  1239
    /// \warning A Node pointing to a removed item
deba@149
  1240
    /// could become valid again later if new nodes are
deba@149
  1241
    /// added to the graph.
deba@149
  1242
    bool valid(Node n) const { return Parent::valid(n); }
deba@149
  1243
    /// Arc validity check
deba@149
  1244
deba@149
  1245
    /// This function gives back true if the given arc is valid,
alpar@209
  1246
    /// ie. it is a real arc of the graph.
deba@149
  1247
    ///
deba@149
  1248
    /// \warning An Arc pointing to a removed item
deba@149
  1249
    /// could become valid again later if new edges are
deba@149
  1250
    /// added to the graph.
deba@149
  1251
    bool valid(Arc a) const { return Parent::valid(a); }
deba@149
  1252
    /// Edge validity check
deba@149
  1253
deba@149
  1254
    /// This function gives back true if the given edge is valid,
alpar@209
  1255
    /// ie. it is a real arc of the graph.
deba@149
  1256
    ///
deba@149
  1257
    /// \warning A Edge pointing to a removed item
deba@149
  1258
    /// could become valid again later if new edges are
deba@149
  1259
    /// added to the graph.
deba@149
  1260
    bool valid(Edge e) const { return Parent::valid(e); }
deba@235
  1261
    /// \brief Change the end \c u of \c e to \c n
deba@57
  1262
    ///
deba@235
  1263
    /// This function changes the end \c u of \c e to node \c n.
deba@57
  1264
    ///
deba@235
  1265
    ///\note The <tt>EdgeIt</tt>s and <tt>ArcIt</tt>s referencing the
deba@235
  1266
    ///changed edge are invalidated and if the changed node is the
deba@235
  1267
    ///base node of an iterator then this iterator is also
deba@235
  1268
    ///invalidated.
kpeter@73
  1269
    ///
kpeter@73
  1270
    ///\warning This functionality cannot be used together with the
kpeter@73
  1271
    ///Snapshot feature.
deba@235
  1272
    void changeU(Edge e, Node n) {
deba@235
  1273
      Parent::changeU(e,n);
alpar@209
  1274
    }
deba@235
  1275
    /// \brief Change the end \c v of \c e to \c n
deba@57
  1276
    ///
deba@235
  1277
    /// This function changes the end \c v of \c e to \c n.
deba@57
  1278
    ///
deba@235
  1279
    ///\note The <tt>EdgeIt</tt>s referencing the changed edge remain
deba@235
  1280
    ///valid, however <tt>ArcIt</tt>s and if the changed node is the
deba@235
  1281
    ///base node of an iterator then this iterator is invalidated.
kpeter@73
  1282
    ///
kpeter@73
  1283
    ///\warning This functionality cannot be used together with the
kpeter@73
  1284
    ///Snapshot feature.
deba@235
  1285
    void changeV(Edge e, Node n) {
deba@235
  1286
      Parent::changeV(e,n);
deba@57
  1287
    }
deba@57
  1288
    /// \brief Contract two nodes.
deba@57
  1289
    ///
deba@57
  1290
    /// This function contracts two nodes.
deba@57
  1291
    /// Node \p b will be removed but instead of deleting
deba@57
  1292
    /// its neighboring arcs, they will be joined to \p a.
deba@57
  1293
    /// The last parameter \p r controls whether to remove loops. \c true
deba@57
  1294
    /// means that loops will be removed.
deba@57
  1295
    ///
deba@57
  1296
    /// \note The <tt>ArcIt</tt>s referencing a moved arc remain
deba@57
  1297
    /// valid.
kpeter@73
  1298
    ///
kpeter@73
  1299
    ///\warning This functionality cannot be used together with the
kpeter@73
  1300
    ///Snapshot feature.
deba@57
  1301
    void contract(Node a, Node b, bool r = true) {
kpeter@73
  1302
      for(IncEdgeIt e(*this, b); e!=INVALID;) {
alpar@209
  1303
        IncEdgeIt f = e; ++f;
alpar@209
  1304
        if (r && runningNode(e) == a) {
alpar@209
  1305
          erase(e);
deba@235
  1306
        } else if (u(e) == b) {
deba@235
  1307
          changeU(e, a);
alpar@209
  1308
        } else {
deba@235
  1309
          changeV(e, a);
alpar@209
  1310
        }
alpar@209
  1311
        e = f;
deba@57
  1312
      }
deba@57
  1313
      erase(b);
deba@57
  1314
    }
deba@57
  1315
deba@57
  1316
kpeter@73
  1317
    /// \brief Class to make a snapshot of the graph and restore
kpeter@73
  1318
    /// it later.
deba@57
  1319
    ///
kpeter@73
  1320
    /// Class to make a snapshot of the graph and restore it later.
deba@57
  1321
    ///
deba@57
  1322
    /// The newly added nodes and edges can be removed
deba@57
  1323
    /// using the restore() function.
deba@57
  1324
    ///
kpeter@73
  1325
    /// \warning Edge and node deletions and other modifications
alpar@209
  1326
    /// (e.g. changing nodes of edges, contracting nodes) cannot be
kpeter@73
  1327
    /// restored. These events invalidate the snapshot.
deba@57
  1328
    class Snapshot {
deba@57
  1329
    protected:
deba@57
  1330
deba@57
  1331
      typedef Parent::NodeNotifier NodeNotifier;
deba@57
  1332
deba@57
  1333
      class NodeObserverProxy : public NodeNotifier::ObserverBase {
deba@57
  1334
      public:
deba@57
  1335
deba@57
  1336
        NodeObserverProxy(Snapshot& _snapshot)
deba@57
  1337
          : snapshot(_snapshot) {}
deba@57
  1338
deba@57
  1339
        using NodeNotifier::ObserverBase::attach;
deba@57
  1340
        using NodeNotifier::ObserverBase::detach;
deba@57
  1341
        using NodeNotifier::ObserverBase::attached;
alpar@209
  1342
deba@57
  1343
      protected:
alpar@209
  1344
deba@57
  1345
        virtual void add(const Node& node) {
deba@57
  1346
          snapshot.addNode(node);
deba@57
  1347
        }
deba@57
  1348
        virtual void add(const std::vector<Node>& nodes) {
deba@57
  1349
          for (int i = nodes.size() - 1; i >= 0; ++i) {
deba@57
  1350
            snapshot.addNode(nodes[i]);
deba@57
  1351
          }
deba@57
  1352
        }
deba@57
  1353
        virtual void erase(const Node& node) {
deba@57
  1354
          snapshot.eraseNode(node);
deba@57
  1355
        }
deba@57
  1356
        virtual void erase(const std::vector<Node>& nodes) {
deba@57
  1357
          for (int i = 0; i < int(nodes.size()); ++i) {
deba@57
  1358
            snapshot.eraseNode(nodes[i]);
deba@57
  1359
          }
deba@57
  1360
        }
deba@57
  1361
        virtual void build() {
deba@57
  1362
          Node node;
deba@57
  1363
          std::vector<Node> nodes;
alpar@209
  1364
          for (notifier()->first(node); node != INVALID;
deba@57
  1365
               notifier()->next(node)) {
deba@57
  1366
            nodes.push_back(node);
deba@57
  1367
          }
deba@57
  1368
          for (int i = nodes.size() - 1; i >= 0; --i) {
deba@57
  1369
            snapshot.addNode(nodes[i]);
deba@57
  1370
          }
deba@57
  1371
        }
deba@57
  1372
        virtual void clear() {
deba@57
  1373
          Node node;
alpar@209
  1374
          for (notifier()->first(node); node != INVALID;
deba@57
  1375
               notifier()->next(node)) {
deba@57
  1376
            snapshot.eraseNode(node);
deba@57
  1377
          }
deba@57
  1378
        }
deba@57
  1379
deba@57
  1380
        Snapshot& snapshot;
deba@57
  1381
      };
deba@57
  1382
deba@57
  1383
      class EdgeObserverProxy : public EdgeNotifier::ObserverBase {
deba@57
  1384
      public:
deba@57
  1385
deba@57
  1386
        EdgeObserverProxy(Snapshot& _snapshot)
deba@57
  1387
          : snapshot(_snapshot) {}
deba@57
  1388
deba@57
  1389
        using EdgeNotifier::ObserverBase::attach;
deba@57
  1390
        using EdgeNotifier::ObserverBase::detach;
deba@57
  1391
        using EdgeNotifier::ObserverBase::attached;
alpar@209
  1392
deba@57
  1393
      protected:
deba@57
  1394
kpeter@73
  1395
        virtual void add(const Edge& edge) {
kpeter@73
  1396
          snapshot.addEdge(edge);
deba@57
  1397
        }
kpeter@73
  1398
        virtual void add(const std::vector<Edge>& edges) {
kpeter@73
  1399
          for (int i = edges.size() - 1; i >= 0; ++i) {
kpeter@73
  1400
            snapshot.addEdge(edges[i]);
deba@57
  1401
          }
deba@57
  1402
        }
kpeter@73
  1403
        virtual void erase(const Edge& edge) {
kpeter@73
  1404
          snapshot.eraseEdge(edge);
deba@57
  1405
        }
kpeter@73
  1406
        virtual void erase(const std::vector<Edge>& edges) {
kpeter@73
  1407
          for (int i = 0; i < int(edges.size()); ++i) {
kpeter@73
  1408
            snapshot.eraseEdge(edges[i]);
deba@57
  1409
          }
deba@57
  1410
        }
deba@57
  1411
        virtual void build() {
kpeter@73
  1412
          Edge edge;
kpeter@73
  1413
          std::vector<Edge> edges;
alpar@209
  1414
          for (notifier()->first(edge); edge != INVALID;
kpeter@73
  1415
               notifier()->next(edge)) {
kpeter@73
  1416
            edges.push_back(edge);
deba@57
  1417
          }
kpeter@73
  1418
          for (int i = edges.size() - 1; i >= 0; --i) {
kpeter@73
  1419
            snapshot.addEdge(edges[i]);
deba@57
  1420
          }
deba@57
  1421
        }
deba@57
  1422
        virtual void clear() {
kpeter@73
  1423
          Edge edge;
alpar@209
  1424
          for (notifier()->first(edge); edge != INVALID;
kpeter@73
  1425
               notifier()->next(edge)) {
kpeter@73
  1426
            snapshot.eraseEdge(edge);
deba@57
  1427
          }
deba@57
  1428
        }
deba@57
  1429
deba@57
  1430
        Snapshot& snapshot;
deba@57
  1431
      };
kpeter@73
  1432
kpeter@73
  1433
      ListGraph *graph;
deba@57
  1434
deba@57
  1435
      NodeObserverProxy node_observer_proxy;
kpeter@73
  1436
      EdgeObserverProxy edge_observer_proxy;
deba@57
  1437
deba@57
  1438
      std::list<Node> added_nodes;
kpeter@73
  1439
      std::list<Edge> added_edges;
deba@57
  1440
deba@57
  1441
deba@57
  1442
      void addNode(const Node& node) {
alpar@209
  1443
        added_nodes.push_front(node);
deba@57
  1444
      }
deba@57
  1445
      void eraseNode(const Node& node) {
alpar@209
  1446
        std::list<Node>::iterator it =
deba@57
  1447
          std::find(added_nodes.begin(), added_nodes.end(), node);
deba@57
  1448
        if (it == added_nodes.end()) {
deba@57
  1449
          clear();
kpeter@73
  1450
          edge_observer_proxy.detach();
deba@57
  1451
          throw NodeNotifier::ImmediateDetach();
deba@57
  1452
        } else {
deba@57
  1453
          added_nodes.erase(it);
deba@57
  1454
        }
deba@57
  1455
      }
deba@57
  1456
kpeter@73
  1457
      void addEdge(const Edge& edge) {
alpar@209
  1458
        added_edges.push_front(edge);
deba@57
  1459
      }
kpeter@73
  1460
      void eraseEdge(const Edge& edge) {
alpar@209
  1461
        std::list<Edge>::iterator it =
kpeter@73
  1462
          std::find(added_edges.begin(), added_edges.end(), edge);
kpeter@73
  1463
        if (it == added_edges.end()) {
deba@57
  1464
          clear();
deba@57
  1465
          node_observer_proxy.detach();
deba@57
  1466
          throw EdgeNotifier::ImmediateDetach();
deba@57
  1467
        } else {
kpeter@73
  1468
          added_edges.erase(it);
kpeter@73
  1469
        }
deba@57
  1470
      }
deba@57
  1471
kpeter@73
  1472
      void attach(ListGraph &_graph) {
alpar@209
  1473
        graph = &_graph;
alpar@209
  1474
        node_observer_proxy.attach(graph->notifier(Node()));
kpeter@73
  1475
        edge_observer_proxy.attach(graph->notifier(Edge()));
deba@57
  1476
      }
alpar@209
  1477
deba@57
  1478
      void detach() {
alpar@209
  1479
        node_observer_proxy.detach();
alpar@209
  1480
        edge_observer_proxy.detach();
deba@57
  1481
      }
deba@57
  1482
deba@57
  1483
      bool attached() const {
deba@57
  1484
        return node_observer_proxy.attached();
deba@57
  1485
      }
deba@57
  1486
deba@57
  1487
      void clear() {
deba@57
  1488
        added_nodes.clear();
alpar@209
  1489
        added_edges.clear();
deba@57
  1490
      }
deba@57
  1491
deba@57
  1492
    public:
deba@57
  1493
deba@57
  1494
      /// \brief Default constructor.
deba@57
  1495
      ///
deba@57
  1496
      /// Default constructor.
deba@57
  1497
      /// To actually make a snapshot you must call save().
alpar@209
  1498
      Snapshot()
alpar@209
  1499
        : graph(0), node_observer_proxy(*this),
kpeter@73
  1500
          edge_observer_proxy(*this) {}
alpar@209
  1501
deba@57
  1502
      /// \brief Constructor that immediately makes a snapshot.
alpar@209
  1503
      ///
kpeter@73
  1504
      /// This constructor immediately makes a snapshot of the graph.
kpeter@73
  1505
      /// \param _graph The graph we make a snapshot of.
alpar@209
  1506
      Snapshot(ListGraph &_graph)
alpar@209
  1507
        : node_observer_proxy(*this),
kpeter@73
  1508
          edge_observer_proxy(*this) {
alpar@209
  1509
        attach(_graph);
deba@57
  1510
      }
alpar@209
  1511
deba@57
  1512
      /// \brief Make a snapshot.
deba@57
  1513
      ///
kpeter@73
  1514
      /// Make a snapshot of the graph.
deba@57
  1515
      ///
deba@57
  1516
      /// This function can be called more than once. In case of a repeated
deba@57
  1517
      /// call, the previous snapshot gets lost.
kpeter@73
  1518
      /// \param _graph The graph we make the snapshot of.
kpeter@73
  1519
      void save(ListGraph &_graph) {
deba@57
  1520
        if (attached()) {
deba@57
  1521
          detach();
deba@57
  1522
          clear();
deba@57
  1523
        }
kpeter@73
  1524
        attach(_graph);
deba@57
  1525
      }
alpar@209
  1526
deba@57
  1527
      /// \brief Undo the changes until the last snapshot.
alpar@209
  1528
      //
deba@57
  1529
      /// Undo the changes until the last snapshot created by save().
deba@57
  1530
      void restore() {
alpar@209
  1531
        detach();
alpar@209
  1532
        for(std::list<Edge>::iterator it = added_edges.begin();
kpeter@73
  1533
            it != added_edges.end(); ++it) {
alpar@209
  1534
          graph->erase(*it);
alpar@209
  1535
        }
alpar@209
  1536
        for(std::list<Node>::iterator it = added_nodes.begin();
deba@57
  1537
            it != added_nodes.end(); ++it) {
alpar@209
  1538
          graph->erase(*it);
alpar@209
  1539
        }
deba@57
  1540
        clear();
deba@57
  1541
      }
deba@57
  1542
deba@57
  1543
      /// \brief Gives back true when the snapshot is valid.
deba@57
  1544
      ///
deba@57
  1545
      /// Gives back true when the snapshot is valid.
deba@57
  1546
      bool valid() const {
deba@57
  1547
        return attached();
deba@57
  1548
      }
deba@57
  1549
    };
deba@57
  1550
  };
alpar@209
  1551
alpar@209
  1552
  /// @}
deba@57
  1553
} //namespace lemon
alpar@209
  1554
deba@57
  1555
deba@57
  1556
#endif