#include<iostream>
#include<cstring> #include<cstdio> #include<queue> using namespace std; #define MAX 110 #define inf 100000000 struct node { int dt; int id; bool operator<(node t)const { return dt < t.dt; } }; priority_queue<node> q; struct edge { int v; int w; int next; } E[2 * MAX *MAX]; int head[MAX]; int num; int dist[MAX]; bool vis[MAX]; int n; int src, des; void init() { memset(head, -1, sizeof(head)); num = 0; int i; for(i = 1; i <= n; i++) dist[i] = inf; memset(vis, 0, sizeof(vis)); } void add(int s, int t, int w) { E[num].v = t; E[num].w = w; E[num].next = head[s]; head[s] = num++; E[num].v = s; E[num].w = w; E[num].next = head[t]; head[t] = num++; } void dijkstra() { while(!q.empty())q.pop(); dist[src] = 0; node bg; bg.dt = 0; bg.id = src; q.push(bg); while(!q.empty()) { node p = q.top(); q.pop(); int u = p.id; if(vis[u])continue; vis[u] = true; int v; for(int i = head[u]; i != -1; i = E[i].next) { int v = E[i].v; if(dist[v] > dist[u] + E[i].w) { dist[v] = dist[u] + E[i].w; node tp; tp.id = v; tp.dt = dist[v]; q.push(tp); } } } } int main() { int m; while(scanf("%d%d", &n, &m) != EOF) { if(n == 0 && m == 0) break; init(); int i; int s, t, w; for(i = 1; i <= m; i++) { scanf("%d%d%d", &s, &t, &w); add(s, t, w); add(t, s, w); } scanf("%d%d", &src, &des); dijkstra(); cout << dist[des] << endl; } } |