kpeter@745: /* -*- mode: C++; indent-tabs-mode: nil; -*-
kpeter@745:  *
kpeter@745:  * This file is a part of LEMON, a generic C++ optimization library.
kpeter@745:  *
kpeter@745:  * Copyright (C) 2003-2009
kpeter@745:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
kpeter@745:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
kpeter@745:  *
kpeter@745:  * Permission to use, modify and distribute this software is granted
kpeter@745:  * provided that this copyright notice appears in all copies. For
kpeter@745:  * precise terms see the accompanying LICENSE file.
kpeter@745:  *
kpeter@745:  * This software is provided "AS IS" with no warranty of any kind,
kpeter@745:  * express or implied, and with no claim as to its suitability for any
kpeter@745:  * purpose.
kpeter@745:  *
kpeter@745:  */
kpeter@745: 
kpeter@745: #include <lemon/concepts/digraph.h>
kpeter@745: #include <lemon/smart_graph.h>
kpeter@745: #include <lemon/list_graph.h>
kpeter@745: #include <lemon/lgf_reader.h>
kpeter@745: #include <lemon/bellman_ford.h>
kpeter@745: #include <lemon/path.h>
kpeter@745: 
kpeter@745: #include "graph_test.h"
kpeter@745: #include "test_tools.h"
kpeter@745: 
kpeter@745: using namespace lemon;
kpeter@745: 
kpeter@745: char test_lgf[] =
kpeter@745:   "@nodes\n"
kpeter@745:   "label\n"
kpeter@745:   "0\n"
kpeter@745:   "1\n"
kpeter@745:   "2\n"
kpeter@745:   "3\n"
kpeter@745:   "4\n"
kpeter@745:   "@arcs\n"
kpeter@745:   "    length\n"
kpeter@745:   "0 1 3\n"
kpeter@745:   "1 2 -3\n"
kpeter@745:   "1 2 -5\n"
kpeter@745:   "1 3 -2\n"
kpeter@745:   "0 2 -1\n"
kpeter@745:   "1 2 -4\n"
kpeter@745:   "0 3 2\n"
kpeter@745:   "4 2 -5\n"
kpeter@745:   "2 3 1\n"
kpeter@745:   "@attributes\n"
kpeter@745:   "source 0\n"
kpeter@745:   "target 3\n";
kpeter@745: 
kpeter@745: 
kpeter@745: void checkBellmanFordCompile()
kpeter@745: {
kpeter@745:   typedef int Value;
kpeter@745:   typedef concepts::Digraph Digraph;
kpeter@745:   typedef concepts::ReadMap<Digraph::Arc,Value> LengthMap;
kpeter@745:   typedef BellmanFord<Digraph, LengthMap> BF;
kpeter@745:   typedef Digraph::Node Node;
kpeter@745:   typedef Digraph::Arc Arc;
kpeter@745: 
kpeter@745:   Digraph gr;
kpeter@745:   Node s, t, n;
kpeter@745:   Arc e;
kpeter@745:   Value l;
kpeter@745:   int k;
kpeter@745:   bool b;
kpeter@745:   BF::DistMap d(gr);
kpeter@745:   BF::PredMap p(gr);
kpeter@745:   LengthMap length;
kpeter@745:   concepts::Path<Digraph> pp;
kpeter@745: 
kpeter@745:   {
kpeter@745:     BF bf_test(gr,length);
kpeter@745:     const BF& const_bf_test = bf_test;
kpeter@745: 
kpeter@745:     bf_test.run(s);
kpeter@745:     bf_test.run(s,k);
kpeter@745: 
kpeter@745:     bf_test.init();
kpeter@745:     bf_test.addSource(s);
kpeter@745:     bf_test.addSource(s, 1);
kpeter@745:     b = bf_test.processNextRound();
kpeter@745:     b = bf_test.processNextWeakRound();
kpeter@745: 
kpeter@745:     bf_test.start();
kpeter@745:     bf_test.checkedStart();
kpeter@745:     bf_test.limitedStart(k);
kpeter@745: 
kpeter@745:     l  = const_bf_test.dist(t);
kpeter@745:     e  = const_bf_test.predArc(t);
kpeter@745:     s  = const_bf_test.predNode(t);
kpeter@745:     b  = const_bf_test.reached(t);
kpeter@745:     d  = const_bf_test.distMap();
kpeter@745:     p  = const_bf_test.predMap();
kpeter@745:     pp = const_bf_test.path(t);
kpeter@828:     pp = const_bf_test.negativeCycle();
kpeter@745:     
kpeter@745:     for (BF::ActiveIt it(const_bf_test); it != INVALID; ++it) {}
kpeter@745:   }
kpeter@745:   {
kpeter@745:     BF::SetPredMap<concepts::ReadWriteMap<Node,Arc> >
kpeter@745:       ::SetDistMap<concepts::ReadWriteMap<Node,Value> >
kpeter@745:       ::SetOperationTraits<BellmanFordDefaultOperationTraits<Value> >
kpeter@745:       ::Create bf_test(gr,length);
kpeter@745: 
kpeter@745:     LengthMap length_map;
kpeter@745:     concepts::ReadWriteMap<Node,Arc> pred_map;
kpeter@745:     concepts::ReadWriteMap<Node,Value> dist_map;
kpeter@745:     
kpeter@745:     bf_test
kpeter@745:       .lengthMap(length_map)
kpeter@745:       .predMap(pred_map)
kpeter@745:       .distMap(dist_map);
kpeter@745: 
kpeter@745:     bf_test.run(s);
kpeter@745:     bf_test.run(s,k);
kpeter@745: 
kpeter@745:     bf_test.init();
kpeter@745:     bf_test.addSource(s);
kpeter@745:     bf_test.addSource(s, 1);
kpeter@745:     b = bf_test.processNextRound();
kpeter@745:     b = bf_test.processNextWeakRound();
kpeter@745: 
kpeter@745:     bf_test.start();
kpeter@745:     bf_test.checkedStart();
kpeter@745:     bf_test.limitedStart(k);
kpeter@745: 
kpeter@745:     l  = bf_test.dist(t);
kpeter@745:     e  = bf_test.predArc(t);
kpeter@745:     s  = bf_test.predNode(t);
kpeter@745:     b  = bf_test.reached(t);
kpeter@745:     pp = bf_test.path(t);
kpeter@828:     pp = bf_test.negativeCycle();
kpeter@745:   }
kpeter@745: }
kpeter@745: 
kpeter@745: void checkBellmanFordFunctionCompile()
kpeter@745: {
kpeter@745:   typedef int Value;
kpeter@745:   typedef concepts::Digraph Digraph;
kpeter@745:   typedef Digraph::Arc Arc;
kpeter@745:   typedef Digraph::Node Node;
kpeter@745:   typedef concepts::ReadMap<Digraph::Arc,Value> LengthMap;
kpeter@745: 
kpeter@745:   Digraph g;
kpeter@745:   bool b;
kpeter@745:   bellmanFord(g,LengthMap()).run(Node());
kpeter@745:   b = bellmanFord(g,LengthMap()).run(Node(),Node());
kpeter@745:   bellmanFord(g,LengthMap())
kpeter@745:     .predMap(concepts::ReadWriteMap<Node,Arc>())
kpeter@745:     .distMap(concepts::ReadWriteMap<Node,Value>())
kpeter@745:     .run(Node());
kpeter@745:   b=bellmanFord(g,LengthMap())
kpeter@745:     .predMap(concepts::ReadWriteMap<Node,Arc>())
kpeter@745:     .distMap(concepts::ReadWriteMap<Node,Value>())
kpeter@745:     .path(concepts::Path<Digraph>())
kpeter@745:     .dist(Value())
kpeter@745:     .run(Node(),Node());
kpeter@745: }
kpeter@745: 
kpeter@745: 
kpeter@745: template <typename Digraph, typename Value>
kpeter@745: void checkBellmanFord() {
kpeter@745:   TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
kpeter@745:   typedef typename Digraph::template ArcMap<Value> LengthMap;
kpeter@745: 
kpeter@745:   Digraph gr;
kpeter@745:   Node s, t;
kpeter@745:   LengthMap length(gr);
kpeter@745: 
kpeter@745:   std::istringstream input(test_lgf);
kpeter@745:   digraphReader(gr, input).
kpeter@745:     arcMap("length", length).
kpeter@745:     node("source", s).
kpeter@745:     node("target", t).
kpeter@745:     run();
kpeter@745: 
kpeter@745:   BellmanFord<Digraph, LengthMap>
kpeter@745:     bf(gr, length);
kpeter@745:   bf.run(s);
kpeter@745:   Path<Digraph> p = bf.path(t);
kpeter@745: 
kpeter@745:   check(bf.reached(t) && bf.dist(t) == -1, "Bellman-Ford found a wrong path.");
kpeter@745:   check(p.length() == 3, "path() found a wrong path.");
kpeter@745:   check(checkPath(gr, p), "path() found a wrong path.");
kpeter@745:   check(pathSource(gr, p) == s, "path() found a wrong path.");
kpeter@745:   check(pathTarget(gr, p) == t, "path() found a wrong path.");
kpeter@745:   
kpeter@745:   ListPath<Digraph> path;
kpeter@745:   Value dist;
kpeter@745:   bool reached = bellmanFord(gr,length).path(path).dist(dist).run(s,t);
kpeter@745: 
kpeter@745:   check(reached && dist == -1, "Bellman-Ford found a wrong path.");
kpeter@745:   check(path.length() == 3, "path() found a wrong path.");
kpeter@745:   check(checkPath(gr, path), "path() found a wrong path.");
kpeter@745:   check(pathSource(gr, path) == s, "path() found a wrong path.");
kpeter@745:   check(pathTarget(gr, path) == t, "path() found a wrong path.");
kpeter@745: 
kpeter@745:   for(ArcIt e(gr); e!=INVALID; ++e) {
kpeter@745:     Node u=gr.source(e);
kpeter@745:     Node v=gr.target(e);
kpeter@745:     check(!bf.reached(u) || (bf.dist(v) - bf.dist(u) <= length[e]),
kpeter@745:           "Wrong output. dist(target)-dist(source)-arc_length=" <<
kpeter@745:           bf.dist(v) - bf.dist(u) - length[e]);
kpeter@745:   }
kpeter@745: 
kpeter@745:   for(NodeIt v(gr); v!=INVALID; ++v) {
kpeter@745:     if (bf.reached(v)) {
kpeter@745:       check(v==s || bf.predArc(v)!=INVALID, "Wrong tree.");
kpeter@745:       if (bf.predArc(v)!=INVALID ) {
kpeter@745:         Arc e=bf.predArc(v);
kpeter@745:         Node u=gr.source(e);
kpeter@745:         check(u==bf.predNode(v),"Wrong tree.");
kpeter@745:         check(bf.dist(v) - bf.dist(u) == length[e],
kpeter@745:               "Wrong distance! Difference: " <<
kpeter@745:               bf.dist(v) - bf.dist(u) - length[e]);
kpeter@745:       }
kpeter@745:     }
kpeter@745:   }
kpeter@745: }
kpeter@745: 
kpeter@746: void checkBellmanFordNegativeCycle() {
kpeter@746:   DIGRAPH_TYPEDEFS(SmartDigraph);
kpeter@746: 
kpeter@746:   SmartDigraph gr;
kpeter@746:   IntArcMap length(gr);
kpeter@746:   
kpeter@746:   Node n1 = gr.addNode();
kpeter@746:   Node n2 = gr.addNode();
kpeter@746:   Node n3 = gr.addNode();
kpeter@746:   Node n4 = gr.addNode();
kpeter@746:   
kpeter@746:   Arc a1 = gr.addArc(n1, n2);
kpeter@746:   Arc a2 = gr.addArc(n2, n2);
kpeter@746:   
kpeter@746:   length[a1] = 2;
kpeter@746:   length[a2] = -1;
kpeter@746:   
kpeter@746:   {
kpeter@746:     BellmanFord<SmartDigraph, IntArcMap> bf(gr, length);
kpeter@746:     bf.run(n1);
kpeter@746:     StaticPath<SmartDigraph> p = bf.negativeCycle();
kpeter@746:     check(p.length() == 1 && p.front() == p.back() && p.front() == a2,
kpeter@746:           "Wrong negative cycle.");
kpeter@746:   }
kpeter@746:  
kpeter@746:   length[a2] = 0;
kpeter@746:   
kpeter@746:   {
kpeter@746:     BellmanFord<SmartDigraph, IntArcMap> bf(gr, length);
kpeter@746:     bf.run(n1);
kpeter@746:     check(bf.negativeCycle().empty(),
kpeter@746:           "Negative cycle should not be found.");
kpeter@746:   }
kpeter@746:   
kpeter@746:   length[gr.addArc(n1, n3)] = 5;
kpeter@746:   length[gr.addArc(n4, n3)] = 1;
kpeter@746:   length[gr.addArc(n2, n4)] = 2;
kpeter@746:   length[gr.addArc(n3, n2)] = -4;
kpeter@746:   
kpeter@746:   {
kpeter@746:     BellmanFord<SmartDigraph, IntArcMap> bf(gr, length);
kpeter@746:     bf.init();
kpeter@746:     bf.addSource(n1);
kpeter@746:     for (int i = 0; i < 4; ++i) {
kpeter@746:       check(bf.negativeCycle().empty(),
kpeter@746:             "Negative cycle should not be found.");
kpeter@746:       bf.processNextRound();
kpeter@746:     }
kpeter@746:     StaticPath<SmartDigraph> p = bf.negativeCycle();
kpeter@746:     check(p.length() == 3, "Wrong negative cycle.");
kpeter@746:     check(length[p.nth(0)] + length[p.nth(1)] + length[p.nth(2)] == -1,
kpeter@746:           "Wrong negative cycle.");
kpeter@746:   }
kpeter@746: }
kpeter@746: 
kpeter@745: int main() {
kpeter@745:   checkBellmanFord<ListDigraph, int>();
kpeter@745:   checkBellmanFord<SmartDigraph, double>();
kpeter@746:   checkBellmanFordNegativeCycle();
kpeter@745:   return 0;
kpeter@745: }