COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/work/jacint/preflow.cc @ 211:9222a9b8b323

Last change on this file since 211:9222a9b8b323 was 211:9222a9b8b323, checked in by jacint, 16 years ago

updating

File size: 2.0 KB
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1#include <iostream>
2#include <fstream>
3
4#include <list_graph.h>
5#include <dimacs.h>
6#include <preflow.h>
7#include <time_measure.h>
8
9using namespace hugo;
10
11// Use a DIMACS max flow file as stdin.
12// read_dimacs_demo < dimacs_max_flow_file
13int main(int, char **) {
14  typedef ListGraph::Node Node;
15  typedef ListGraph::EdgeIt EdgeIt;
16
17  ListGraph G;
18  Node s, t;
19  ListGraph::EdgeMap<int> cap(G);
20  readDimacsMaxFlow(std::cin, G, s, t, cap);
21
22  std::cout << "preflow demo ..." << std::endl;
23 
24  double mintime=1000000;
25
26  for ( int i=1; i!=11; ++i ) {
27    ListGraph::EdgeMap<int> flow(G);
28    double pre_time=currTime();
29    Preflow<ListGraph, int> max_flow_test(G, s, t, cap, flow);
30    max_flow_test.run();
31    double post_time=currTime();
32    if ( mintime > post_time-pre_time ) mintime = post_time-pre_time;
33  }
34
35  ListGraph::EdgeMap<int> flow(G);
36  Preflow<ListGraph, int> max_flow_test(G, s, t, cap, flow);
37  max_flow_test.run();
38 
39  ListGraph::NodeMap<bool> cut(G);
40  max_flow_test.minCut(cut);
41  int min_cut_value=0;
42  EdgeIt e;
43  for(G.first(e); G.valid(e); G.next(e)) {
44    if (cut.get(G.tail(e)) && !cut.get(G.head(e))) min_cut_value+=cap.get(e);
45  }
46
47  ListGraph::NodeMap<bool> cut1(G);
48  max_flow_test.minMinCut(cut1);
49  int min_min_cut_value=0;
50  for(G.first(e); G.valid(e); G.next(e)) {
51    if (cut.get(G.tail(e)) && !cut.get(G.head(e)))
52      min_min_cut_value+=cap.get(e);
53  }
54
55  ListGraph::NodeMap<bool> cut2(G);
56  max_flow_test.maxMinCut(cut2);
57  int max_min_cut_value=0;
58  for(G.first(e); G.valid(e); G.next(e)) {
59    if (cut2.get(G.tail(e)) && !cut2.get(G.head(e)))
60      max_min_cut_value+=cap.get(e);
61      }
62 
63  std::cout << "min time of 10 runs: " << mintime << " sec"<< std::endl;
64  std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
65  std::cout << "min cut value: "<< min_cut_value << std::endl;
66  std::cout << "min min cut value: "<< min_min_cut_value << std::endl;
67  std::cout << "max min cut value: "<< max_min_cut_value <<
68    std::endl<< std::endl;
69 
70  return 0;
71}
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