Computing the number of the connected components and the components themselves.
7 #include <lemon/smart_graph.h>
8 #include <lemon/dijkstra.h>
9 #include <lemon/floyd_warshall.h>
10 #include <lemon/johnson.h>
12 #include <lemon/time_measure.h>
13 #include "test_tools.h"
15 using namespace lemon;
18 int main(int argc, const char *argv[]) {
20 typedef SmartGraph Graph;
21 typedef Graph::Node Node;
22 typedef Graph::Edge Edge;
23 typedef Graph::NodeIt NodeIt;
24 typedef Graph::EdgeIt EdgeIt;
26 typedef Graph::EdgeMap<double> LengthMap;
27 typedef Graph::NodeMap<double> DistMap;
29 const int n = argc > 1 ? atoi(argv[1]) : 20;
30 const int e = argc > 2 ? atoi(argv[2]) : (int)(n * log((double)n));
31 const double m = argc > 3 ? (double)atoi(argv[3]) : 100.0;
34 LengthMap length(graph);
38 for (int i = 0; i < n; ++i) {
39 Node node = graph.addNode();
40 nodes.push_back(node);
41 shift[node] = m * (double)rand() / (RAND_MAX + 1.0);
44 for (int i = 0; i < e; ++i) {
45 int s = (int)(n * (double)rand() / (RAND_MAX + 1.0));
46 int t = (int)(n * (double)rand() / (RAND_MAX + 1.0));
47 double c = m * (double)rand() / (RAND_MAX + 1.0);
48 Edge edge = graph.addEdge(nodes[s], nodes[t]);
49 length[edge] = c - shift[nodes[s]] + shift[nodes[t]];
52 Johnson<Graph, LengthMap> johnson(graph, length);
56 cout << "Johnson: " << timer << endl;
59 FloydWarshall<Graph, LengthMap> floyd(graph, length);
63 cout << "FloydWarshall: " << timer << endl;
66 for (NodeIt it(graph); it != INVALID; ++it) {
67 for (NodeIt jt(graph); jt != INVALID; ++jt) {
68 check(johnson.connected(it, jt) == floyd.connected(it, jt),
69 "Wrong connection in all pairs shortest path");
70 if (johnson.connected(it, jt)) {
71 check(johnson.dist(it, jt) == floyd.dist(it, jt),
72 "Wrong distance in all pairs shortest path");
74 check(johnson.dist(it, jt) ==
75 johnson.dist(it, johnson.predNode(it, jt)) +
76 length[johnson.pred(it, jt)],
77 "Wrong edge in all pairs shortest path");
78 check(floyd.dist(it, jt) ==
79 floyd.dist(it, floyd.predNode(it, jt)) +
80 length[floyd.pred(it, jt)],
81 "Wrong edge in all pairs shortest path");