test/kruskal_test.cc
author kpeter
Thu, 28 Feb 2008 02:54:27 +0000
changeset 2581 054566ac0934
parent 2424 95cd24940d00
permissions -rw-r--r--
Query improvements in the min cost flow algorithms.

- External flow and potential maps can be used.
- New query functions: flow() and potential().
- CycleCanceling also provides dual solution (node potentials).
- Doc improvements.
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #include <iostream>
    20 #include <vector>
    21 
    22 #include "test_tools.h"
    23 #include <lemon/maps.h>
    24 #include <lemon/kruskal.h>
    25 #include <lemon/list_graph.h>
    26 
    27 #include <lemon/concepts/maps.h>
    28 #include <lemon/concepts/graph.h>
    29 #include <lemon/concepts/ugraph.h>
    30 
    31 
    32 using namespace std;
    33 using namespace lemon;
    34 
    35 void checkCompileKruskal()
    36 {
    37   concepts::WriteMap<concepts::Graph::Edge,bool> w;
    38   concepts::WriteMap<concepts::UGraph::UEdge,bool> uw;
    39 
    40   concepts::ReadMap<concepts::Graph::Edge,int> r;
    41   concepts::ReadMap<concepts::UGraph::UEdge,int> ur;
    42 
    43   concepts::Graph g;
    44   concepts::UGraph ug;
    45 
    46   kruskal(g, r, w);
    47   kruskal(ug, ur, uw);
    48 
    49   std::vector<std::pair<concepts::Graph::Edge, int> > rs;
    50   std::vector<std::pair<concepts::UGraph::UEdge, int> > urs;
    51 
    52   kruskal(g, rs, w);
    53   kruskal(ug, urs, uw);
    54 
    55   std::vector<concepts::Graph::Edge> ws;
    56   std::vector<concepts::UGraph::UEdge> uws;
    57 
    58   kruskal(g, r, ws.begin());
    59   kruskal(ug, ur, uws.begin());
    60 
    61   Kruskal<concepts::UGraph,concepts::ReadMap<concepts::UGraph::UEdge,int> >
    62     alg(ug, ur);
    63 
    64   alg.init();
    65   alg.initPresorted(uws.begin(), uws.end());
    66   alg.reinit();
    67   
    68   alg.emptyQueue();
    69   
    70   alg.nextEdge();
    71   alg.processNextEdge();
    72   alg.processEdge(concepts::UGraph::UEdge());
    73 
    74   alg.run();
    75   
    76   alg.treeMap();
    77   alg.tree(concepts::UGraph::UEdge());
    78 }
    79 
    80 int main() {
    81 
    82   typedef ListUGraph::Node Node;
    83   typedef ListUGraph::UEdge UEdge;
    84   typedef ListUGraph::NodeIt NodeIt;
    85   typedef ListUGraph::EdgeIt EdgeIt;
    86 
    87   ListUGraph G;
    88 
    89   Node s=G.addNode();
    90   Node v1=G.addNode();
    91   Node v2=G.addNode();
    92   Node v3=G.addNode();
    93   Node v4=G.addNode();
    94   Node t=G.addNode();
    95   
    96   UEdge e1 = G.addEdge(s, v1);
    97   UEdge e2 = G.addEdge(s, v2);
    98   UEdge e3 = G.addEdge(v1, v2);
    99   UEdge e4 = G.addEdge(v2, v1);
   100   UEdge e5 = G.addEdge(v1, v3);
   101   UEdge e6 = G.addEdge(v3, v2);
   102   UEdge e7 = G.addEdge(v2, v4);
   103   UEdge e8 = G.addEdge(v4, v3);
   104   UEdge e9 = G.addEdge(v3, t);
   105   UEdge e10 = G.addEdge(v4, t);
   106 
   107   typedef ListUGraph::UEdgeMap<int> ECostMap;
   108   typedef ListUGraph::UEdgeMap<bool> EBoolMap;
   109 
   110   ECostMap edge_cost_map(G, 2);
   111   EBoolMap tree_map(G);
   112   
   113 
   114   //Test with const map.
   115   check(kruskal(G, ConstMap<ListUGraph::UEdge,int>(2), tree_map)==10,
   116 	"Total cost should be 10");
   117   //Test with a edge map (filled with uniform costs).
   118   check(kruskal(G, edge_cost_map, tree_map)==10,
   119 	"Total cost should be 10");
   120 
   121   edge_cost_map.set(e1, -10);
   122   edge_cost_map.set(e2, -9);
   123   edge_cost_map.set(e3, -8);
   124   edge_cost_map.set(e4, -7);
   125   edge_cost_map.set(e5, -6);
   126   edge_cost_map.set(e6, -5);
   127   edge_cost_map.set(e7, -4);
   128   edge_cost_map.set(e8, -3);
   129   edge_cost_map.set(e9, -2);
   130   edge_cost_map.set(e10, -1);
   131 
   132   vector<UEdge> tree_edge_vec(5);
   133 
   134   //Test with a edge map and inserter.
   135   check(kruskal(G, edge_cost_map,
   136 		 tree_edge_vec.begin())
   137 	==-31,
   138 	"Total cost should be -31.");
   139   
   140   tree_edge_vec.clear();
   141 
   142   check(kruskal(G, edge_cost_map,
   143 		back_inserter(tree_edge_vec))
   144 	==-31,
   145 	"Total cost should be -31.");
   146   
   147 //   tree_edge_vec.clear();
   148   
   149 //   //The above test could also be coded like this:
   150 //   check(kruskal(G,
   151 // 		makeKruskalMapInput(G, edge_cost_map),
   152 // 		makeKruskalSequenceOutput(back_inserter(tree_edge_vec)))
   153 // 	==-31,
   154 // 	"Total cost should be -31.");
   155 
   156   check(tree_edge_vec.size()==5,"The tree should have 5 edges.");
   157 
   158   check(tree_edge_vec[0]==e1 &&
   159 	tree_edge_vec[1]==e2 &&
   160 	tree_edge_vec[2]==e5 &&
   161 	tree_edge_vec[3]==e7 &&
   162 	tree_edge_vec[4]==e9,
   163 	"Wrong tree.");
   164 
   165   Kruskal<ListUGraph, ECostMap> ka(G, edge_cost_map);
   166   
   167   ka.run();
   168   
   169   check(ka.tree(e1) && 
   170         ka.tree(e2) &&
   171         ka.tree(e5) &&
   172         ka.tree(e7) &&
   173         ka.tree(e9),
   174         "Wrong tree.");
   175 
   176   check(ka.treeValue() == -31,
   177 	"Total cost should be -31.");
   178 
   179   return 0;
   180 }