lemon/random.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 06 Aug 2009 20:12:43 +0200
changeset 760 83ce7ce39f21
parent 209 765619b7cbb2
permissions -rw-r--r--
Rework and fix the implementation of MinMeanCycle (#179)

- Fix the handling of the cycle means.
- Many implementation improvements:
- More efficient data storage for the strongly connected
components.
- Better handling of BFS queues.
- Merge consecutive BFS searches (perform two BFS searches
instead of three).

This version is about two times faster on average and an order of
magnitude faster if there are a lot of strongly connected components.
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2009
     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 ///\file
    20 ///\brief Instantiation of the Random class.
    21 
    22 #include <lemon/random.h>
    23 
    24 namespace lemon {
    25   /// \brief Global random number generator instance
    26   ///
    27   /// A global Mersenne Twister random number generator instance.
    28   Random rnd;
    29 }