//============================================================================
// Name        : Graph_AL.cpp
// Author      : Arnaud Lange
// Version     : 1.0
// Copyright   : Your copyright notice
// Description : Classic Dijkstra
//============================================================================

//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee, 
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <stdlib.h>

//using namespace std;
#include <time.h>

#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>

using namespace boost;

int
main(int, char *[])
{
  typedef adjacency_list < listS, vecS, undirectedS,
    no_property, property < edge_weight_t, float > > graph_t;
  typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor;
  typedef graph_traits < graph_t >::edge_descriptor edge_descriptor;
  typedef std::pair<float, float> Edge;

  time_t start, end;
  double dif;
  time(&start);
  
  //const int num_nodes = 5;
  //enum nodes { A, B, C, D, E };
  int NX, NY, num_nodes, num_arcs;
  int i, j, k, kv;
  std::cout << "NX: ";
  std::cin >> NX;std::cout << std::endl;
  std::cout << "NY: ";
  std::cin >> NY;std::cout << std::endl;
  num_nodes = NX*NY;
  num_arcs = 2*(NX-1)*(NY-1)+NY+NX-2;
  
  std::cout << "Num nodes: " << num_nodes << std::endl;
  std::cout << "Num arcs: " << num_arcs << std::endl;
  //int nodes[]={0,1,2,3,4};
  //char name[] = "ABCDE";
  /* Edge edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E),
    Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B)
  };*/
  /* Edge edge_array[] = { Edge(0, 2), Edge(1, 1), Edge(1, 3), Edge(1, 4),
      Edge(2, 1), Edge(2, 3), Edge(3, 4), Edge(4, 0), Edge(4, 1)
    }; */
  
  // Initialize random seed
  //srand(time(NULL));
  
  //int nodes[num_nodes];
  Edge edge_array[num_arcs];
  float weights[num_arcs];
  int n1, n2;
  k=0;kv=0;

  for (j=0; j<=NY-2; j++)
  {
	  for (i=0; i<=NX-2; i++)
	  {
		n1=i+j*NX;n2=(i+1)+j*NX;
		edge_array[k]=Edge(n1, n2);
		//weights[k]=1+rand()%10;
		weights[k]=0.5;
		//std::cout << "Weight " << k << " : " << weights[k] << std::endl;
		k++;
		n2=i+(j+1)*NX;
	    edge_array[k]=Edge(n1, n2);	
	    //weights[k]=1+rand()%10;
	    weights[k]=0.5;
	    //std::cout << "Weight " << k << " : " << weights[k] << std::endl;
	    k++;
	    //nodes[kv]=kv;
	    kv++;
	  }
	  n1=(NX-1)+j*NX;n2=(NX-1)+(j+1)*NX;
	  edge_array[k]=Edge(n1, n2);
	  //weights[k]=1+rand()%10;
	  weights[k]=0.5;
	  //std::cout << "Weight " << k << " : " << weights[k] << std::endl;
	  k++;
	  //nodes[kv]=kv;
	  kv++;
  }
  for (i=0; i<=NX-2; i++)
  {
	  n1=i+(NY-1)*NX;n2=(i+1)+(NY-1)*NX;
	  edge_array[k]=Edge(n1, n2);
	  //weights[k]=1+rand()%10;
	  weights[k]=0.5;
	  //std::cout << "Weight " << k << " : " << weights[k] << std::endl;
	  k++;
	  //nodes[kv]=kv;
	  kv++;
  }
  //nodes[kv]=kv;




  time(&end);
  dif = difftime(end,start);
  std::cout << "Construction time = " << dif << std::endl;
  
  // int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 };
  
  //int num_arcs = sizeof(edge_array) / sizeof(Edge);
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
  graph_t g(num_nodes);
  property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
  for (std::size_t j = 0; j < num_arcs; ++j) {
    edge_descriptor e; bool inserted;
    tie(e, inserted) = add_edge(edge_array[j].first, edge_array[j].second, g);
    weightmap[e] = weights[j];
  }
#else
  graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes);
  //property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
#endif
  std::vector<vertex_descriptor> p(num_vertices(g));
  std::vector<float> d(num_vertices(g));
  int ini_v;
  //ini_v = rand()%num_nodes;
  ini_v=0;
  std::cout << "Init vertex: " << ini_v << std::endl;
  vertex_descriptor s = vertex(ini_v, g);

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
  // VC++ has trouble with the named parameters mechanism
  property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g);
  dijkstra_shortest_paths(g, s, &p[0], &d[0], weightmap, indexmap, 
                          std::less<float>(), closed_plus<float>(),
                          (std::numeric_limits<float>::max)(), 0,
                          default_dijkstra_visitor());
#else
  dijkstra_shortest_paths(g, s, predecessor_map(&p[0]).distance_map(&d[0]));
#endif

  std::cout << "distances and parents:" << std::endl;
  graph_traits < graph_t >::vertex_iterator vi, vend;
  k=0;
  for (tie(vi, vend) = vertices(g); (vi != vend)&&(k<15); ++vi) {
    //std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", ";
   // std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std::endl;
    std::cout << "distance(" << *vi << ") = " << d[*vi] << ", ";
    std::cout << "parent(" << *vi << ") = " << p[*vi] << std::endl;
    k++;
  }
  std::cout << std::endl;

  /*
  std::ofstream dot_file("figs/dijkstra-eg.dot");

  dot_file << "digraph D {\n"
    << "  rankdir=LR\n"
    << "  size=\"4,3\"\n"
    << "  ratio=\"fill\"\n"
    << "  edge[style=\"bold\"]\n" << "  node[shape=\"circle\"]\n";

  graph_traits < graph_t >::edge_iterator ei, ei_end;
  for (tie(ei, ei_end) = edges(g); ei != ei_end; ++ei) {
    graph_traits < graph_t >::edge_descriptor e = *ei;
    graph_traits < graph_t >::vertex_descriptor
      u = source(e, g), v = target(e, g);
    dot_file << name[u] << " -> " << name[v]
      << "[label=\"" << get(weightmap, e) << "\"";
    if (p[v] == u)
      dot_file << ", color=\"black\"";
    else
      dot_file << ", color=\"grey\"";
    dot_file << "]";
  }
  dot_file << "}";
  */
  
  time(&end);
  dif = difftime(end,start);
  std::cout << "Computation time = " << dif << std::endl;
  
  return EXIT_SUCCESS;
}