src/work/jacint/graph_gen.h
author jacint
Thu, 06 May 2004 09:26:23 +0000
changeset 538 d8863141824d
child 558 4cbfb435ec2b
permissions -rw-r--r--
(none)
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// -*- c++ -*-
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//randomGraph(i,j) gives a random graph on i nodes and j edges.
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#include <vector>
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#include <cstdlib>
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//#include <list_graph.h>
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//#include <time_measure.h>
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//#include <for_each_macros.h>
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//#include <bfs_iterator.h>
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//#include <bipartite_graph_wrapper.h>
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//#include <maps.h>
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//#include <max_flow.h>
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namespace hugo {
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  /**
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   * Inicializalja a veletlenszamgeneratort.
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   * Figyelem, ez nem jo igazi random szamokhoz,
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   * erre ne bizzad a titkaidat!
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   */
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  void random_init()
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  {
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    unsigned int seed = getpid();
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    seed |= seed << 15;
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    seed ^= time(0);
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    srand(seed);
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  }
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  /**
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   * Egy veletlen int-et ad vissza 0 es m-1 kozott.
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   */
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  int random(int m)
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  {
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    return int( double(m) * rand() / (RAND_MAX + 1.0) );
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  }
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  template<typename Graph>
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  void randomGraph (Graph& g, int n, int m) {
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    typedef typename Graph::Node Node;
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    g.clear();
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    std::vector<Node> nodes;
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    for (int i=0; i<n; ++i)
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      nodes.push_back(g.addNode());
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    for (int i=0; i<m; ++i) 
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      g.addEdge(nodes[random(n)], nodes[random(n)]);
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  }
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}