benchmark/graph-bench.cc
author kpeter
Mon, 18 Feb 2008 03:34:16 +0000
changeset 2577 2c6204d4b0f6
parent 2391 14a343be7a5a
child 2590 47c245b97199
permissions -rw-r--r--
Add a cost scaling min cost flow algorithm.

Add a cost scaling algorithm, which is performing generalized
push-relabel operations. It is almost as efficient as the capacity
scaling algorithm, but slower than network simplex.
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     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/list_graph.h>
    20 
    21 #include"bench_tools.h"
    22 
    23 using namespace lemon;
    24 
    25 ///Makes a full graph by adding and deleting a lot of edges;
    26 
    27 ///\param n Number of nodes.
    28 ///\param rat The funcion will make \f$rat\timesn^2\f$ edge addition and
    29 ///\f$(rat-1)\timesn^2\f$ deletion.
    30 ///\param p Tuning parameters.
    31 ///\warning \c rat, \c p, and \c n must be pairwise relative primes. 
    32 template <class Graph>
    33 void makeFullGraph(int n, int rat, int p)
    34 {
    35   GRAPH_TYPEDEFS(typename Graph);
    36 
    37   Graph G;
    38   
    39   //  Node nodes[n];
    40   std::vector<Node> nodes(n);
    41   for(int i=0;i<n;i++) nodes[i]=G.addNode();
    42   
    43   //Edge equ[rat];
    44   std::vector<Edge> equ(rat);
    45   
    46   long long int count;
    47   
    48   for(count=0;count<rat;count++) {
    49     equ[int(count%rat)]=G.addEdge(nodes[int((count*p)%n)],
    50 				  nodes[int((count*p/n)%n)]);
    51   }
    52   for(;(count%rat)||((count*p)%n)||((count*p/n)%n);count++) {
    53     //    if(!(count%1000000)) fprintf(stderr,"%d\r",count);
    54     if(count%rat) G.erase(equ[count%rat]);
    55     equ[int(count%rat)]=G.addEdge(nodes[int((count*p)%n)],
    56 				  nodes[int((count*p/n)%n)]);
    57   }
    58 //   std::cout << "Added " << count
    59 // 	    << " ( " << n << "^2 * " << rat << " ) edges\n";
    60 
    61 
    62   //  for(int i=0;1;i++) ;
    63 }
    64 
    65 int main()
    66 {
    67   lemon::Timer T;
    68   makeFullGraph<ListGraph>(nextPrim(1000),nextPrim(300),nextPrim(100));
    69   
    70   PrintTime("BIG",T);
    71   T.restart();
    72   makeFullGraph<ListGraph>(nextPrim(100),nextPrim(30000),nextPrim(150));
    73 
    74   PrintTime("SMALL",T);
    75 }