test/kruskal_test.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Tue, 15 Mar 2011 19:32:21 +0100
changeset 936 ddd3c0d3d9bf
parent 440 88ed40ad0d4f
permissions -rw-r--r--
Implement the scaling Price Refinement heuristic in CostScaling (#417)
instead of Early Termination.

These two heuristics are similar, but the newer one is faster
and not only makes it possible to skip some epsilon phases, but
it can improve the performance of the other phases, as well.
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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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#include <iostream>
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#include <vector>
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#include "test_tools.h"
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#include <lemon/maps.h>
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#include <lemon/kruskal.h>
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#include <lemon/list_graph.h>
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#include <lemon/concepts/maps.h>
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#include <lemon/concepts/digraph.h>
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#include <lemon/concepts/graph.h>
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using namespace std;
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using namespace lemon;
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void checkCompileKruskal()
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{
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  concepts::WriteMap<concepts::Digraph::Arc,bool> w;
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  concepts::WriteMap<concepts::Graph::Edge,bool> uw;
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  concepts::ReadMap<concepts::Digraph::Arc,int> r;
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  concepts::ReadMap<concepts::Graph::Edge,int> ur;
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  concepts::Digraph g;
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  concepts::Graph ug;
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  kruskal(g, r, w);
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  kruskal(ug, ur, uw);
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  std::vector<std::pair<concepts::Digraph::Arc, int> > rs;
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  std::vector<std::pair<concepts::Graph::Edge, int> > urs;
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  kruskal(g, rs, w);
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  kruskal(ug, urs, uw);
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  std::vector<concepts::Digraph::Arc> ws;
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  std::vector<concepts::Graph::Edge> uws;
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  kruskal(g, r, ws.begin());
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  kruskal(ug, ur, uws.begin());
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}
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int main() {
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  typedef ListGraph::Node Node;
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  typedef ListGraph::Edge Edge;
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  typedef ListGraph::NodeIt NodeIt;
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  typedef ListGraph::ArcIt ArcIt;
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  ListGraph G;
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  Node s=G.addNode();
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  Node v1=G.addNode();
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  Node v2=G.addNode();
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  Node v3=G.addNode();
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  Node v4=G.addNode();
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  Node t=G.addNode();
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  Edge e1 = G.addEdge(s, v1);
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  Edge e2 = G.addEdge(s, v2);
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  Edge e3 = G.addEdge(v1, v2);
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  Edge e4 = G.addEdge(v2, v1);
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  Edge e5 = G.addEdge(v1, v3);
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  Edge e6 = G.addEdge(v3, v2);
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  Edge e7 = G.addEdge(v2, v4);
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  Edge e8 = G.addEdge(v4, v3);
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  Edge e9 = G.addEdge(v3, t);
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  Edge e10 = G.addEdge(v4, t);
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  typedef ListGraph::EdgeMap<int> ECostMap;
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  typedef ListGraph::EdgeMap<bool> EBoolMap;
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  ECostMap edge_cost_map(G, 2);
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  EBoolMap tree_map(G);
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  //Test with const map.
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  check(kruskal(G, ConstMap<ListGraph::Edge,int>(2), tree_map)==10,
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        "Total cost should be 10");
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  //Test with an edge map (filled with uniform costs).
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  check(kruskal(G, edge_cost_map, tree_map)==10,
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        "Total cost should be 10");
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  edge_cost_map[e1] = -10;
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  edge_cost_map[e2] = -9;
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  edge_cost_map[e3] = -8;
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  edge_cost_map[e4] = -7;
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  edge_cost_map[e5] = -6;
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  edge_cost_map[e6] = -5;
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  edge_cost_map[e7] = -4;
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  edge_cost_map[e8] = -3;
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  edge_cost_map[e9] = -2;
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  edge_cost_map[e10] = -1;
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  vector<Edge> tree_edge_vec(5);
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  //Test with a edge map and inserter.
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  check(kruskal(G, edge_cost_map,
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                 tree_edge_vec.begin())
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        ==-31,
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        "Total cost should be -31.");
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  tree_edge_vec.clear();
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  check(kruskal(G, edge_cost_map,
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                back_inserter(tree_edge_vec))
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        ==-31,
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        "Total cost should be -31.");
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//   tree_edge_vec.clear();
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//   //The above test could also be coded like this:
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//   check(kruskal(G,
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//                 makeKruskalMapInput(G, edge_cost_map),
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//                 makeKruskalSequenceOutput(back_inserter(tree_edge_vec)))
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//         ==-31,
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//         "Total cost should be -31.");
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  check(tree_edge_vec.size()==5,"The tree should have 5 edges.");
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  check(tree_edge_vec[0]==e1 &&
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        tree_edge_vec[1]==e2 &&
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        tree_edge_vec[2]==e5 &&
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        tree_edge_vec[3]==e7 &&
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        tree_edge_vec[4]==e9,
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        "Wrong tree.");
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  return 0;
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}