fork(3) download 
  1. #include <iostream>
  2. #include <iomanip>
  3.  
  4. #include <boost/graph/grid_graph.hpp>
  5. #include <boost/graph/detail/d_ary_heap.hpp>
  6. #include <boost/property_map/property_map.hpp>
  7.  
  8. #include <cstdlib>
  9.  
  10. template <typename TQueue>
  11. static void OutputQueue(TQueue queue);
  12.  
  13. int main(int, char*[])
  14. {
  15.   srand((unsigned int)time(NULL));
  16.   srand48((unsigned int)time(NULL));
  17.  
  18.   boost::array<std::size_t, 2> lengths = { { 2,2 } };
  19.   typedef boost::grid_graph<2> GraphType;
  20.   GraphType graph(lengths);
  21.   typedef boost::graph_traits<GraphType>::vertex_descriptor Vertex;
  22.   typedef boost::property_map<GraphType, boost::vertex_index_t>::const_type GridIndexMapType;
  23.   GridIndexMapType gridIndexMap(get(boost::vertex_index, graph));
  24.  
  25.   typedef boost::vector_property_map<std::size_t, GridIndexMapType> IndexInHeapMap;
  26.   IndexInHeapMap index_in_heap(gridIndexMap);
  27.  
  28.   typedef boost::graph_traits<GraphType>::vertex_iterator VertexIteratorType;
  29.  
  30.   typedef boost::vector_property_map<float, GridIndexMapType> PriorityMapType;
  31.   PriorityMapType priorityMap(gridIndexMap);
  32.   VertexIteratorType vertexIterator, vertexIteratorEnd;
  33.  
  34.   typedef std::greater<float> ComparisonFunctor;
  35.   typedef boost::d_ary_heap_indirect<Vertex, 4, IndexInHeapMap, PriorityMapType, ComparisonFunctor > MutableQueueType;
  36.  
  37.   ComparisonFunctor comparisonFunctor;
  38.   MutableQueueType mutableQueue(priorityMap, index_in_heap, comparisonFunctor);
  39.  
  40.   std::cout << "There are " << mutableQueue.size() << " items in the queue." << std::endl;
  41.  
  42.   // Add random values to the vertices and add them to the queue
  43.   for( tie(vertexIterator, vertexIteratorEnd) = vertices(graph); vertexIterator != vertexIteratorEnd; ++vertexIterator)
  44.   {
  45.     float newPriority = rand() % 1000;
  46.     std::cout << "New priority for " << vertexIterator->operator[](0) << ", " << vertexIterator->operator[](1) << " " << newPriority << std::endl;
  47.     put(priorityMap, *vertexIterator, newPriority);
  48.   }
  49.  
  50.   for( tie(vertexIterator, vertexIteratorEnd) = vertices(graph); vertexIterator != vertexIteratorEnd; ++vertexIterator)
  51.   {
  52.     mutableQueue.push(*vertexIterator);
  53.   }
  54.  
  55.   std::cout << "There are " << mutableQueue.size() << " items in the queue." << std::endl;
  56.  
  57.   std::cout << "The priority queue is: " << std::endl;
  58.   OutputQueue(mutableQueue);
  59.  
  60.   // Insert another set of random values for each vertex
  61.   for( tie(vertexIterator, vertexIteratorEnd) = vertices(graph); vertexIterator != vertexIteratorEnd; ++vertexIterator)
  62.   {
  63.     float newPriority = rand() % 1000;
  64.     std::cout << "New priority for " << vertexIterator->operator[](0) << ", " << vertexIterator->operator[](1) << " " << newPriority << std::endl;
  65.     put(priorityMap, *vertexIterator, newPriority);
  66.     mutableQueue.update(*vertexIterator);
  67.   }
  68.  
  69.   std::cout << "There are " << mutableQueue.size() << " items in the queue." << std::endl;
  70.  
  71.   std::cout << "The priority queue is: " << std::endl;
  72.   OutputQueue(mutableQueue);
  73.  
  74.   std::cout << std::endl;
  75.  
  76.   return 0;
  77. }
  78.  
  79. template <typename TQueue>
  80. static void OutputQueue(TQueue queue)
  81. {
  82.   while( ! queue.empty() )
  83.   {
  84.     typename TQueue::value_type u = queue.top();
  85.  
  86.     // These two lines are equivalent
  87.     std::cout << "vertex: " << u[0] << " " << u[1] << " priority: " << get(queue.keys(), u) << std::endl;
  88.  
  89.     queue.pop();
  90.   }
  91. }
  92.  
Compilation error #stdin compilation error #stdout 0s 0KB
comments (?)
stdin 
Standard input is empty
compilation info 
prog.cpp:4:38: error: boost/graph/grid_graph.hpp: No such file or directory
prog.cpp:5:45: error: boost/graph/detail/d_ary_heap.hpp: No such file or directory
prog.cpp:6:47: error: boost/property_map/property_map.hpp: No such file or directory
prog.cpp: In function ‘int main(int, char**)’:
prog.cpp:18: error: ‘boost’ has not been declared
prog.cpp:18: error: expected primary-expression before ‘,’ token
prog.cpp:18: error: ‘lengths’ was not declared in this scope
prog.cpp:18: error: expected primary-expression before ‘{’ token
prog.cpp:18: error: expected `;' before ‘{’ token
prog.cpp:91: error: expected `}' at end of input
stdout 
Standard output is empty
https://ideone.com/gfEMp
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!