/* -*- C++ -*-

  * src/test/dijkstra_heap_test.cc - Part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Combinatorial Optimization Research Group, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 //Tests dijsktra.h with two heap implementations:

 //the default binary heap of bin_heap.h, and the 

 //Fibonacci heap of fib_heap.h.

 //The input is a graph in standard dimacs format from the standard input (like

 //in /lemon_loc/testfiles/dimacs). It runs dijkstra.h on this graph with both

 //heaps, checking two postconditions:

 //- if the edges e=uv of the shortest path tree reported by dijkstra.h have

 //dist(v)-dist(u)=length(e)

 // - if all edges e=uv with u reachable from the root have

 //dist(v)-dist(u)>=length(e)

 #include <iostream>

 #include <math.h>

 #include <lemon/smart_graph.h>

 #include <lemon/graph_writer.h>

 #include <lemon/map_utils.h>

 #include <lemon/dimacs.h>

 #include <lemon/dijkstra.h>

 #include <lemon/time_measure.h>

 #include <lemon/graph_utils.h>

 #include <lemon/bin_heap.h>

 #include <lemon/fib_heap.h>

 #include <lemon/radix_heap.h>

 using namespace lemon;

 typedef ListGraph Graph;

 typedef Graph::Edge Edge;

 typedef Graph::Node Node;

 typedef Graph::EdgeIt EdgeIt;

 typedef Graph::NodeIt NodeIt;

 typedef Graph::EdgeMap<int> LengthMap;

 struct FibTraits : public DijkstraDefaultTraits<Graph, LengthMap> {

   typedef FibHeap<Graph::Node, LengthMap::Value, Graph::NodeMap<int> > Heap;

 };

 struct RadixTraits : public DijkstraDefaultTraits<Graph, LengthMap> {

   typedef RadixHeap<Graph::Node, Graph::NodeMap<int> > Heap;

 };

 int main(int argc, const char* argv[]) {

   Graph graph;

   Node s, t;

   LengthMap cap(graph);

   readDimacs(std::cin, graph, cap, s, t);

   Timer ts;

   GraphWriter<Graph> writer(std::cout, graph);

   IdMap<Graph, Node> nodeIdMap(graph);

   writer.addNodeMap("id", nodeIdMap);

   IdMap<Graph, Edge> edgeIdMap(graph);

   writer.addEdgeMap("id", edgeIdMap);

   writer.addEdgeMap("cap", cap);

   writer.run();

   std::cout <<

     "\n  Testing dijkstra.h with binary heap implementation bin_heap.h,"

 	    <<std::endl;

   std::cout<<"  on a graph with " << 

     countNodes(graph) << " nodes and " << countEdges(graph) << " edges..."

 	   << std::endl<<std::endl;

   Dijkstra<Graph, LengthMap> 

     dijkstra_test(graph, cap);

   ts.reset();

    dijkstra_test.run(s);

   std::cout << "elapsed time: " << ts << std::endl;

   int error1=0;

   int error2=0;

   for(EdgeIt e(graph); e!=INVALID; ++e) {

     Node u=graph.source(e); 

     Node v=graph.target(e);

     if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) > cap[e] )

       if ( dijkstra_test.reached(u) ) {

 	std::cout<<"Error! dist(target)-dist(source)- edge_length= " 

 		 <<dijkstra_test.dist(v) - dijkstra_test.dist(u) 

 	  - cap[e]<<std::endl;

 	++error1;

       }

   }

   NodeIt v;

   for(NodeIt v(graph); v!=INVALID; ++v) {

     if ( dijkstra_test.reached(v) ) {

       Edge e=dijkstra_test.pred(v);

       Node u=graph.source(e);

       if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) != cap[e] ) {

 	std::cout<<"Error in a shortest path tree edge! Difference: " 

 		 <<std::abs(dijkstra_test.dist(v) - dijkstra_test.dist(u) 

 			    - cap[e])<<std::endl;

 	++error2;

       }

     }

   }

   std::cout << error1 << " non-tree and " << error2 

 	    << " shortest path tree edge is erroneous."<<std::endl;

   std::cout <<

     "\n\n  Testing dijkstra.h with Fibonacci heap implementation fib_heap.h,"

 	    <<std::endl;

   std::cout<<"  on a graph with " << 

     countNodes(graph) << " nodes and " << countEdges(graph) << " edges..."

 	   << std::endl<<std::endl;

   Dijkstra<Graph, LengthMap, FibTraits> 

     dijkstra_test2(graph, cap);

   ts.reset();

   dijkstra_test2.run(s);

   std::cout << "elapsed time: " << ts << std::endl;

   error1=0;

   error2=0;

   for(EdgeIt e(graph); e!=INVALID; ++e) {

     Node u=graph.source(e);

     Node v=graph.target(e);

     if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) > cap[e] )

       if ( dijkstra_test2.reached(u) ) {

 	std::cout<<"Error! dist(target)-dist(source)- edge_length= " 

 		 <<dijkstra_test2.dist(v) - dijkstra_test2.dist(u) 

 	  - cap[e]<<std::endl;

 	++error1;

       }

   }

   for(NodeIt n(graph); v!=INVALID; ++v) {

     if ( dijkstra_test2.reached(v) ) {

       Edge e=dijkstra_test2.pred(v);

       Node u=graph.source(e);

       if ( dijkstra_test2.dist(v) - dijkstra_test2.dist(u) != cap[e] ) {

 	std::cout<<"Error in a shortest path tree edge! Difference: " 

 		 <<std::abs(dijkstra_test2.dist(v) - dijkstra_test2.dist(u) 

 			    - cap[e])<<std::endl;

 	++error2;

       }

     }

   }

   std::cout << error1 << " non-tree and " << error2 

 	    << " shortest path tree edge is erroneous."<<std::endl;

   std::cout <<

     "\n\n  Testing dijkstra.h with Radix heap implementation radix_heap.h,"

 	    <<std::endl;

   std::cout<<"  on a graph with " << 

     countNodes(graph) << " nodes and " << countEdges(graph) << " edges..."

 	   << std::endl<<std::endl;

   Dijkstra<Graph, LengthMap, RadixTraits> 

     dijkstra_test3(graph, cap);

   ts.reset();

   dijkstra_test3.run(s);

   std::cout << "elapsed time: " << ts << std::endl;

   error1=0;

   error2=0;

   for(EdgeIt e(graph); e!=INVALID; ++e) {

     Node u=graph.source(e);

     Node v=graph.target(e);

     if ( dijkstra_test3.dist(v) - dijkstra_test3.dist(u) > cap[e] )

       if ( dijkstra_test3.reached(u) ) {

 	std::cout<<"Error! dist(target)-dist(source)- edge_length= " 

 		 <<dijkstra_test3.dist(v) - dijkstra_test3.dist(u) 

 	  - cap[e]<<std::endl;

 	++error1;

       }

   }

   for(NodeIt n(graph); v!=INVALID; ++v) {

     if ( dijkstra_test3.reached(v) ) {

       Edge e=dijkstra_test3.pred(v);

       Node u=graph.source(e);

       if ( dijkstra_test3.dist(v) - dijkstra_test3.dist(u) != cap[e] ) {

 	std::cout<<"Error in a shortest path tree edge! Difference: " 

 		 <<std::abs(dijkstra_test3.dist(v) - dijkstra_test3.dist(u) 

 			    - cap[e])<<std::endl;

 	++error2;

       }

     }

   }

   std::cout << error1 << " non-tree and " << error2 

 	    << " shortest path tree edge is erroneous."<<std::endl;

   return 0;

 }