最短路径C ++ STL的打印路径

Question

我是基于STL的c ++用法的新手。谁能帮助我如何在打印＆＃34;顶点路径＆＃34;中继续使用以下代码？这产生了每个目的地顶点的最短路径得分以及最短路径值。

请找到geeksforgeeks平台的工作代码链接。

http://ide.geeksforgeeks.org/index.php //使用STL set

编程找到Dijkstra的最短路径

#include<bits/stdc++.h>
using namespace std;
# define INF 0x3f3f3f3f

// This class represents a directed graph using 
// adjacency list representation
class Graph
{
    int V; // No. of vertices

    // In a weighted graph, we need to store vertex 
    // and weight pair for every edge
    list< pair<int, int> > *adj;

public:
    Graph(int V); // Constructor

    // function to add an edge to graph
    void addEdge(int u, int v, int w);

    // prints shortest path from s
    void shortestPath(int s);
};

// Allocates memory for adjacency list
Graph::Graph(int V)
{
    this->V = V;
    adj = new list< pair<int, int> >[V];
}

void Graph::addEdge(int u, int v, int w)
{
    adj[u].push_back(make_pair(v, w));
    adj[v].push_back(make_pair(u, w));
}

// Prints shortest paths from src to all other vertices
void Graph::shortestPath(int src)
{
    // Create a set to store vertices that are being
    // prerocessed
    set< pair<int, int> > setds;

    // Create a vector for distances and initialize all
    // distances as infinite (INF)
    vector<int> dist(V, INF);

    // Insert source itself in Set and initialize its
    // distance as 0.
    setds.insert(make_pair(0, src));
    dist[src] = 0;

    /* Looping till all shortest distance are finalized
    then setds will become empty */
    while (!setds.empty())
    {
        // The first vertex in Set is the minimum distance
        // vertex, extract it from set.
        pair<int, int> tmp = *(setds.begin());
        setds.erase(setds.begin());

        // vertex label is stored in second of pair (it
        // has to be done this way to keep the vertices
        // sorted distance (distance must be first item
        // in pair)
        int u = tmp.second;

        // 'i' is used to get all adjacent vertices of a vertex
        list< pair<int, int> >::iterator i;
        for (i = adj[u].begin(); i != adj[u].end(); ++i)
        {
            // Get vertex label and weight of current adjacent
            // of u.
            int v = (*i).first;
            int weight = (*i).second;

            // If there is shorter path to v through u.
            if (dist[v] > dist[u] + weight)
            {
                /* If distance of v is not INF then it must be in
                    our set, so removing it and inserting again
                    with updated less distance. 
                    Note : We extract only those vertices from Set
                    for which distance is finalized. So for them, 
                    we would never reach here. */
                if (dist[v] != INF)
                    setds.erase(setds.find(make_pair(dist[v], v)));

                // Updating distance of v
                dist[v] = dist[u] + weight;
                setds.insert(make_pair(dist[v], v));
            }
        }
    }

    // Print shortest distances stored in dist[]
    printf("Vertex Distance from Source\n");
    for (int i = 0; i < V; ++i)
        printf("%d \t\t %d\n", i, dist[i]);
}

// Driver program to test methods of graph class
int main()
{
    // create the graph given in above fugure
    int V = 9;
    Graph g(V);

    // making above shown graph
    g.addEdge(0, 1, 4);
    g.addEdge(0, 7, 8);
    g.addEdge(1, 2, 8);
    g.addEdge(1, 7, 11);
    g.addEdge(2, 3, 7);
    g.addEdge(2, 8, 2);
    g.addEdge(2, 5, 4);
    g.addEdge(3, 4, 9);
    g.addEdge(3, 5, 14);
    g.addEdge(4, 5, 10);
    g.addEdge(5, 6, 2);
    g.addEdge(6, 7, 1);
    g.addEdge(6, 8, 6);
    g.addEdge(7, 8, 7);

    g.shortestPath(0);

    return 0;
}