背景：我是一个黑客，无论如何不是一个好的程序员，FORTRAN实际上是我的语言，需要一些帮助这个增强代码。当我实现它时，我在向量的第779行得到了'向量下标超出范围'错误。这是我的代码，非常感谢任何帮助！
程序从文件读取边缘，构建图形，然后我想计算从一个顶点到所有其他顶点的距离。
问题似乎应该很容易解决，但我很挣扎，谢谢！
-Jeff
#include "stdafx.h"
#include <stdexcept>
#include <boost/graph/adjacency_list.hpp>
#include <iostream>
#include <utility>
#include <algorithm>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <boost/graph/compressed_sparse_row_graph.hpp>
#include <boost/graph/dijkstra_shortest_paths_no_color_map.hpp>
#include <fstream>
#include <string>
#include <stdio.h>
#include <time.h>
#include <iostream>
using namespace std;
using namespace boost;
int main()
{
long int num_nodes;
long int num_edges;
char *gfile ; //graph data file
char buffer[128] ;
istringstream instream ;
gfile="grid.out";
ifstream infile( gfile, ios::in );
infile.getline(buffer, 128);
instream.clear() ;
instream.str(buffer) ;
instream >> num_nodes >> num_edges;
float wt; // Allocate n ints and save ptr in a.
int num_arcs = num_edges;
int n1,n2;
cout << "READING graph into C++ program from file grid.out"; cout << endl;cout << endl; cout << endl;
cout << "Found ";cout << num_nodes; cout << " nodes, and "; cout << num_edges; cout << " edges";cout << endl;
typedef std::pair < int, int > Edge;
struct Edge_Cost
{
double weight;
};
struct vertex_data {
boost::graph_traits<
boost::compressed_sparse_row_graph< boost::directedS > >::vertex_descriptor p;
double d;
};
typedef boost::compressed_sparse_row_graph<
boost::directedS,
vertex_data,
Edge_Cost
> graph_t;
typedef boost::graph_traits < graph_t >::vertex_descriptor
vertex_descriptor;
graph_t* Graph;
std::vector<vertex_descriptor> p;//path
std::vector<double> d; //distance
int numb_edges = num_edges;
Edge* edge_list = new Edge [numb_edges];
Edge* ptr_edge_list = edge_list;
Edge_Cost* edge_weight_list = new Edge_Cost[numb_edges];
Edge_Cost* ptr_edge_weight_list = edge_weight_list;
for (int i=0; i<num_edges; ++i)
{
//get a line from the file, vertex n1 is linked to vertex n2 by weight wt, but first vertex in file is 1 not 0, so -1
//here is an example of the file:
//grid.out: first line is nvertex, nedges
//10 10
//1 2 0.296033428
//2 3 0.038954928
//3 4 0.080953663
//4 5 0.917876269
//5 6 0.026168687
//6 7 0.037261078
//7 8 0.409351058
//8 9 0.398426038
//9 10 0.942112529
//10 11 0.006422981
infile.getline(buffer, 128);
instream.clear() ;
instream.str(buffer) ;
instream >> n1 >> n2 >> wt;
*ptr_edge_list++ = Edge(n1-1,n2-1);
(ptr_edge_weight_list++)->weight =wt;
}
Graph = new graph_t(boost::edges_are_unsorted,edge_list,ptr_edge_list,edge_weight_list,num_nodes);
vertex_descriptor s = vertex(1,*Graph);
//get one set of distances
boost::dijkstra_shortest_paths_no_color_map
(*Graph,s,
boost::predecessor_map(&p[0]).
distance_map(&d[0]).
weight_map(boost::get(&Edge_Cost::weight, *Graph))
);
return 0;
}
答案 0 :(得分：1)
Graph类型必须是Vertex List Graph和Incidence Graph的模型。 docs
了解http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/compressed_sparse_row.html#models的显示方式：
compressed_sparse_row_graph类模板模型（即 实现了许多BGL图概念的要求， 允许它与大多数BGL算法一起使用。特别是， 它模拟了以下特定图形概念：
- 图形
- 的 IncidenceGraph的
- AdjacencyGraph
- 的点列表图VertexListGraph
- 边列表图EdgeListGraph
- 属性图PropertyGraph
这应该是可能的。 Lemme尝试并在一瞬间回发
阿。这个问题有点误导。错误是您没有在距离和前任地图中预留足够的空间。
前趋映射记录最小生成树中的边。完成算法后，V中所有u的边（p [u]，u）都在最小生成树中。如果p [u] = u，则u是源顶点或无法从源访问的顶点。 PredecessorMap类型必须是图的读/写属性映射
whose key and value types are the same as the vertex descriptor类型。
换句话说，使用足够高的容量来寻址最高的顶点描述符（样本中的11）
从源顶点start_vertex到图形图中每个顶点的最短路径权重记录在此属性映射中。最短路径权重是沿最短路径的边缘权重之和。 DistanceMap类型必须是读/写属性映射的模型。图的顶点描述符类型需要可用作距离图的密钥类型
在此，同样适用。
这是 Live On Coliru 代码的清理
new（以及缺失的delete[]）getline的不安全缓冲区
cout个语句合并为一行// Allocate n ints and save ptr in a.？）#include <algorithm>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/compressed_sparse_row_graph.hpp>
#include <boost/graph/dijkstra_shortest_paths_no_color_map.hpp>
#include <fstream>
#include <iostream>
#include <stdexcept>
#include <string>
#include <utility>
using namespace boost;
int main()
{
std::ifstream infile("input.txt", std::ios::in);
long int num_nodes;
long int num_edges;
{
std::string line;
std::getline(infile, line);
std::istringstream instream(line);
instream >> num_nodes >> num_edges;
}
std::cout << "READING graph into C++ program from file" << std::endl;
std::cout << "Found " << num_nodes << " nodes, and " << num_edges << " edges" << std::endl;
typedef std::pair < int, int > Edge;
struct Edge_Cost
{
double weight;
};
struct vertex_data
{
boost::graph_traits<
boost::compressed_sparse_row_graph< boost::directedS > >::vertex_descriptor p;
double d;
};
typedef boost::compressed_sparse_row_graph<
boost::directedS,
vertex_data,
Edge_Cost
> graph_t;
typedef boost::graph_traits < graph_t >::vertex_descriptor
vertex_descriptor;
std::vector<Edge> edge_list;
std::vector<Edge_Cost> edge_weight_list;
for(int i=0; i<num_edges; ++i)
{
float wt;
int n1,n2;
//get a line from the file, vertex n1 is linked to vertex n2 by weight
//wt, but first vertex in file is 1 not 0, so -1
std::string line;
std::getline(infile, line);
std::istringstream instream(line);
instream >> n1 >> n2 >> wt;
edge_list.emplace_back(n1-1, n2-1);
edge_weight_list.push_back(Edge_Cost{wt});
std::cout << "Read: " << n1 << " " << n2 << " " << wt << "\n";
}
graph_t Graph(boost::edges_are_unsorted,edge_list.begin(),edge_list.end(),&edge_weight_list[0],edge_list.size());
vertex_descriptor s = vertex(1,Graph);
std::vector<vertex_descriptor> p(11);//path
std::vector<double> d(11); //distance
//get one set of distances
boost::dijkstra_shortest_paths_no_color_map
(Graph,s,
boost::predecessor_map(&p[0]).
distance_map(&d[0]).
weight_map(boost::get(&Edge_Cost::weight, Graph))
);
}