学习链式前向星：http://blog.csdn.net/acdreamers/article/details/16902023
留个链式前向星+Dijkstra模板。
1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 #include <vector> 5 #include <queue> 6 using namespace std; 7 #define next Next 8 const int maxn = 1e3+50; 9 const int inf = 0x3f3f3f3f; 10 11 struct Edge 12 { 13 int to; 14 int w; 15 int next; ///以i为起点，该条边的下一条 16 friend bool operator < (Edge A,Edge B) 17 { 18 return A.w>B.w; 19 } 20 }; 21 int cnt; 22 int head[maxn]; ///表示以i为起点的边的最大编号，逆序来 23 int vis[maxn]; 24 int d[maxn]; 25 Edge e[maxn*2]; ///双向边 26 void init() 27 { 28 memset(head,-1,sizeof(head)); 29 cnt = 0; 30 } 31 void addedge(int u,int v,int w) 32 { 33 e[cnt].to = v; 34 e[cnt].w = w; 35 e[cnt].next = head[u]; 36 head[u] = cnt++; 37 } 38 void dijkstra(int s) 39 { 40 memset(vis,0,sizeof(vis)); 41 memset(d,inf,sizeof(d)); 42 d[s] = 0; 43 priority_queue<Edge> q; 44 q.push((Edge){s,0}); 45 while(!q.empty()) 46 { 47 Edge cur = q.top(); 48 int u = cur.to; 49 q.pop(); 50 if(vis[u]) continue; 51 vis[u] = 1; 52 for(int i=head[u];~i;i=e[i].next) 53 { 54 int v = e[i].to; 55 if(d[v]>d[u]+e[i].w) 56 { 57 d[v] = d[u]+e[i].w; 58 q.push((Edge){v,d[v]}); 59 } 60 } 61 } 62 } 63 int main() 64 { 65 int n,m; 66 while(scanf("%d %d",&n,&m)!=EOF) 67 { 68 init(); 69 int a,b,x; 70 for(int i=1;i<=m;i++) 71 { 72 scanf("%d %d %d",&a,&b,&x); 73 addedge(a,b,x); 74 addedge(b,a,x); 75 } 76 int s,t; 77 scanf("%d %d",&s,&t); 78 dijkstra(s); 79 if(d[t]!=inf) 80 printf("%d ",d[t]); 81 else puts("-1"); 82 } 83 return 0; 84 }