1
该代码找到最短路径,但它不考虑是否可以达到目的地。如何在运行此功能之前检查目标是否可达?如何确定两个节点是否相互连接?
void Trains::shortestPath(int src, int dest)
{
set< pair<int, int> > setds;
vector<int> dist(V, INF);
setds.insert(make_pair(0, src));
dist[src] = 0;
while (!setds.empty())
{
pair<int, int> tmp = *(setds.begin());
setds.erase(setds.begin());
int u = tmp.second;
list< pair<int, int> >::iterator i;
for (i = adj[u].begin(); i != adj[u].end(); ++i)
{
int v = (*i).first;
int weight = (*i).second;
if (dist[v] > dist[u] + weight)
{
if (dist[v] != INF)
setds.erase(setds.find(make_pair(dist[v], v)));
dist[v] = dist[u] + weight;
setds.insert(make_pair(dist[v], v));
}
}
}
printf("Vertex Distance from Source\n");
printf("%d \t\t %d\n", dest, dist[dest]);
}
输出:
Vertex Distance from Source
4 73
,如果你想看到所有的代码,这是略有http://www.geeksforgeeks.org/dijkstras-shortest-path-algorithm-using-set-in-stl/修改。
你认为'if(dist [v]!= INF)'是做什么的? – kabanus