UVA 10986 By ACReaper

来源：互联网发布：mac词典编辑：程序博客网时间：2024/05/21 13:57

这题太水了，就不分析了。直接代码

#include <cstdio>#include <vector>#include <queue>using namespace std;const int maxn = 20006;const int INF = 0x6fffffff;typedef pair<int,int> pii;priority_queue<pii,vector<pii>,greater<pii> >q;vector<pii> g[maxn];void Dijkstra(int src);int d[maxn];int main(){int N,n,m,s,t;scanf("%d",&N);for(int i = 1; i <= N; i++){scanf("%d%d%d%d",&n,&m,&s,&t);int u,v,w;for(int j = 0; j < maxn; j++)g[j].clear();for(int j = 1; j <= m; j++){//Build graph scanf("%d%d%d",&u,&v,&w);g[u].push_back(make_pair(w,v));g[v].push_back(make_pair(w,u));}Dijkstra(s);printf("Case #%d: ",i);if(d[t] < INF)printf("%d\n",d[t]);elseputs("unreachable");}} void Dijkstra(int src){while(!q.empty())q.pop();for(int i = 0; i < maxn; i++)d[i] = INF;d[src] = 0;q.push(make_pair(d[src],src));while(!q.empty()){pii x = q.top();q.pop();int u = x.second;if(x.first != d[u]) continue;for(int j = 0; j < g[u].size(); j++){int v = g[u][j].second;int w = g[u][j].first;if(d[v] > d[u] + w){d[v] = d[u] + w;q.push(make_pair(d[v],v));}}}}

2013 05 15

By ACReaper