source: lemon-0.x/test/kruskal_test.cc @ 2125:2f2cbe4e78a8

/* -*- C++ -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2003-2006
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#include <iostream>
#include <vector>

#include "test_tools.h"
#include <lemon/maps.h>
#include <lemon/kruskal.h>
#include <lemon/list_graph.h>
#include <lemon/concept/maps.h>
#include <lemon/concept/graph.h>


using namespace std;
using namespace lemon;

void checkCompileKruskal()
{
  concept::WriteMap<concept::Graph::Edge,bool> w;

  kruskal(concept::Graph(),
          concept::ReadMap<concept::Graph::Edge,int>(),
          w);
}

int main() {

  typedef ListGraph::Node Node;
  typedef ListGraph::Edge Edge;
  typedef ListGraph::NodeIt NodeIt;
  typedef ListGraph::EdgeIt EdgeIt;

  ListGraph G;

  Node s=G.addNode();
  Node v1=G.addNode();
  Node v2=G.addNode();
  Node v3=G.addNode();
  Node v4=G.addNode();
  Node t=G.addNode();
  
  Edge e1 = G.addEdge(s, v1);
  Edge e2 = G.addEdge(s, v2);
  Edge e3 = G.addEdge(v1, v2);
  Edge e4 = G.addEdge(v2, v1);
  Edge e5 = G.addEdge(v1, v3);
  Edge e6 = G.addEdge(v3, v2);
  Edge e7 = G.addEdge(v2, v4);
  Edge e8 = G.addEdge(v4, v3);
  Edge e9 = G.addEdge(v3, t);
  Edge e10 = G.addEdge(v4, t);

  typedef ListGraph::EdgeMap<int> ECostMap;
  typedef ListGraph::EdgeMap<bool> EBoolMap;

  ECostMap edge_cost_map(G, 2);
  EBoolMap tree_map(G);
  

  //Test with const map.
  check(kruskal(G, ConstMap<ListGraph::Edge,int>(2), tree_map)==10,
        "Total cost should be 10");
  //Test with a edge map (filled with uniform costs).
  check(kruskal(G, edge_cost_map, tree_map)==10,
        "Total cost should be 10");

  edge_cost_map.set(e1, -10);
  edge_cost_map.set(e2, -9);
  edge_cost_map.set(e3, -8);
  edge_cost_map.set(e4, -7);
  edge_cost_map.set(e5, -6);
  edge_cost_map.set(e6, -5);
  edge_cost_map.set(e7, -4);
  edge_cost_map.set(e8, -3);
  edge_cost_map.set(e9, -2);
  edge_cost_map.set(e10, -1);

  vector<Edge> tree_edge_vec(5);

  //Test with a edge map and inserter.
  check(kruskal(G, edge_cost_map,
                 tree_edge_vec.begin())
        ==-31,
        "Total cost should be -31.");
  
  tree_edge_vec.clear();

  check(kruskal(G, edge_cost_map,
                back_inserter(tree_edge_vec))
        ==-31,
        "Total cost should be -31.");
  
  tree_edge_vec.clear();
  
  //The above test could also be coded like this:
  check(kruskal(G,
                makeKruskalMapInput(G, edge_cost_map),
                makeKruskalSequenceOutput(back_inserter(tree_edge_vec)))
        ==-31,
        "Total cost should be -31.");

  check(tree_edge_vec.size()==5,"The tree should have 5 edges.");

  check(tree_edge_vec[0]==e1 &&
        tree_edge_vec[1]==e2 &&
        tree_edge_vec[2]==e5 &&
        tree_edge_vec[3]==e7 &&
        tree_edge_vec[4]==e9,
        "Wrong tree.");

  return 0;
}