Location: LEMON/LEMON-official/test/gomory_hu_test.cc

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kpeter (Peter Kovacs)
Add artificial addNode() function to the arc/edge set classes
#include <iostream>
#include "test_tools.h"
#include <lemon/smart_graph.h>
#include <lemon/concepts/graph.h>
#include <lemon/concepts/maps.h>
#include <lemon/lgf_reader.h>
#include <lemon/gomory_hu.h>
#include <cstdlib>
using namespace std;
using namespace lemon;
typedef SmartGraph Graph;
char test_lgf[] =
"@nodes\n"
"label\n"
"0\n"
"1\n"
"2\n"
"3\n"
"4\n"
"@arcs\n"
" label capacity\n"
"0 1 0 1\n"
"1 2 1 1\n"
"2 3 2 1\n"
"0 3 4 5\n"
"0 3 5 10\n"
"0 3 6 7\n"
"4 2 7 1\n"
"@attributes\n"
"source 0\n"
"target 3\n";
void checkGomoryHuCompile()
{
typedef int Value;
typedef concepts::Graph Graph;
typedef Graph::Node Node;
typedef Graph::Edge Edge;
typedef concepts::ReadMap<Edge, Value> CapMap;
typedef concepts::ReadWriteMap<Node, bool> CutMap;
Graph g;
Node n;
CapMap cap;
CutMap cut;
Value v;
int d;
GomoryHu<Graph, CapMap> gh_test(g, cap);
const GomoryHu<Graph, CapMap>&
const_gh_test = gh_test;
gh_test.run();
n = const_gh_test.predNode(n);
v = const_gh_test.predValue(n);
d = const_gh_test.rootDist(n);
v = const_gh_test.minCutValue(n, n);
v = const_gh_test.minCutMap(n, n, cut);
}
GRAPH_TYPEDEFS(Graph);
typedef Graph::EdgeMap<int> IntEdgeMap;
typedef Graph::NodeMap<bool> BoolNodeMap;
int cutValue(const Graph& graph, const BoolNodeMap& cut,
const IntEdgeMap& capacity) {
int sum = 0;
for (EdgeIt e(graph); e != INVALID; ++e) {
Node s = graph.u(e);
Node t = graph.v(e);
if (cut[s] != cut[t]) {
sum += capacity[e];
}
}
return sum;
}
int main() {
Graph graph;
IntEdgeMap capacity(graph);
std::istringstream input(test_lgf);
GraphReader<Graph>(graph, input).
edgeMap("capacity", capacity).run();
GomoryHu<Graph> ght(graph, capacity);
ght.run();
for (NodeIt u(graph); u != INVALID; ++u) {
for (NodeIt v(graph); v != u; ++v) {
Preflow<Graph, IntEdgeMap> pf(graph, capacity, u, v);
pf.runMinCut();
BoolNodeMap cm(graph);
ght.minCutMap(u, v, cm);
check(pf.flowValue() == ght.minCutValue(u, v), "Wrong cut 1");
check(cm[u] != cm[v], "Wrong cut 2");
check(pf.flowValue() == cutValue(graph, cm, capacity), "Wrong cut 3");
int sum=0;
for(GomoryHu<Graph>::MinCutEdgeIt a(ght, u, v);a!=INVALID;++a)
sum+=capacity[a];
check(sum == ght.minCutValue(u, v), "Problem with MinCutEdgeIt");
sum=0;
for(GomoryHu<Graph>::MinCutNodeIt n(ght, u, v,true);n!=INVALID;++n)
sum++;
for(GomoryHu<Graph>::MinCutNodeIt n(ght, u, v,false);n!=INVALID;++n)
sum++;
check(sum == countNodes(graph), "Problem with MinCutNodeIt");
}
}
return 0;
}