benchmark/min_cut_graphs.h
author deba
Wed, 07 Mar 2007 12:00:59 +0000
changeset 2400 b199ded24c19
parent 2341 46a6311ceffa
child 2553 bfced05fa852
permissions -rw-r--r--
Steiner 2-approximation demo
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2007
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #include <lemon/random.h>
    20 
    21 
    22 template <typename UGraph, typename CapacityMap>
    23 void genNoiUGraph(UGraph& g, CapacityMap& c, 
    24                   int n, int d, int k, int p) {
    25   std::vector<typename UGraph::Node> nodes(n);
    26   for (int i = 0; i < n; ++i) {
    27     nodes[i] = g.addNode();
    28   }
    29   typename UGraph::template NodeMap<int> comp(g);
    30   for (int i = 0; i < n; ++i) {
    31     comp[nodes[i]] = rnd[k];
    32   }
    33   int m = (n * (n - 1) * d) / 200;
    34   for (int i = 0; i < m; ++i) {
    35     int s = rnd[n], t = rnd[n];
    36     c[g.addEdge(nodes[s], nodes[t])] =
    37       rnd[(comp[nodes[s]] == comp[nodes[t]] ? p : 1) * 100]; 
    38   }
    39 }
    40 
    41 template <typename UGraph, typename CapacityMap>
    42 void genBikeWheelUGraph(UGraph& g, CapacityMap& c, int n) {
    43   std::vector<typename UGraph::Node> nodes(n);
    44   for (int i = 0; i < n; ++i) {
    45     nodes[i] = g.addNode();
    46   }
    47   for (int i = 0; i < n - 2; ++i) {
    48     c[g.addEdge(nodes[i], nodes[n - 1 - (i % 2)])] = 2;
    49   }
    50   for (int i = 1; i < n - 2; ++i) {
    51     c[g.addEdge(nodes[i - 1], nodes[i])] = n - 1;
    52   }
    53   c[g.addEdge(nodes[n - 3], nodes[0])] = n - 1;
    54   c[g.addEdge(nodes[n - 2], nodes[n - 1])] = 2;
    55 }
    56 
    57 template <typename UGraph, typename CapacityMap>
    58 void genRegUGraph(UGraph& g, CapacityMap& c, int n, int d) {
    59   std::vector<typename UGraph::Node> nodes(n);
    60   for (int i = 0; i < n; ++i) {
    61     nodes[i] = g.addNode();
    62   }
    63   for (int k = 0; k < d; ++k) {
    64     for (int i = 0; i < n; ++i) {
    65       int r = rnd[n];
    66       typename UGraph::Node t = nodes[r];
    67       nodes[r] = nodes[i];
    68       nodes[i] = t;
    69     }
    70     for (int i = 1; i < n; ++i) {
    71       c[g.addEdge(nodes[i - 1], nodes[i])] = 1;
    72     }
    73     c[g.addEdge(nodes[n - 1], nodes[0])] = 1;
    74   }
    75 }
    76 
    77 template <typename UGraph, typename CapacityMap>
    78 void genCdgUGraph(UGraph& g, CapacityMap& c, int n, int d) {
    79   std::vector<typename UGraph::Node> nodes(n);
    80   for (int i = 0; i < n; ++i) {
    81     nodes[i] = g.addNode();
    82   }
    83   std::vector<typename UGraph::Node> mix(n * d);
    84   for (int i = 0; i < n; ++i) {
    85     for (int j = 0; j < d; ++j) {
    86       mix[i * d + j] = nodes[i];
    87     }
    88   }
    89   while (mix.size() >= 2) {
    90     int r;
    91     r = rnd[mix.size()];
    92     typename UGraph::Node s = mix[r];
    93     mix[r] = mix.back(); mix.pop_back();
    94     r = rnd[mix.size()];
    95     typename UGraph::Node t = mix[r];
    96     mix[r] = mix.back(); mix.pop_back();
    97     c[g.addEdge(s, t)] = 1;
    98   }
    99 }