src/demo/kruskal_demo.cc
author alpar
Fri, 08 Apr 2005 14:40:37 +0000
changeset 1326 85f1c483279e
permissions -rw-r--r--
Add presolver() to turn on/off the GLPK presolver
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#include <iostream>
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#include <vector>
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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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using namespace std;
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using namespace lemon;
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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::EdgeIt EdgeIt;
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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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  std::cout << "The weight of the minimum spanning tree is " << kruskalEdgeMap(G, ConstMap<ListGraph::Edge,int>(2), tree_map)<<std::endl;
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/*
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  ==10,
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	"Total cost should be 10");
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  //Test with a edge map (filled with uniform costs).
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  check(kruskalEdgeMap(G, edge_cost_map, tree_map)==10,
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	"Total cost should be 10");
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  edge_cost_map.set(e1, -10);
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  edge_cost_map.set(e2, -9);
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  edge_cost_map.set(e3, -8);
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  edge_cost_map.set(e4, -7);
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  edge_cost_map.set(e5, -6);
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  edge_cost_map.set(e6, -5);
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  edge_cost_map.set(e7, -4);
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  edge_cost_map.set(e8, -3);
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  edge_cost_map.set(e9, -2);
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  edge_cost_map.set(e10, -1);
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  vector<Edge> tree_edge_vec;
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  //Test with a edge map and inserter.
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  check(kruskalEdgeMap_IteratorOut(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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*/
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  return 0;
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}