poj 2387 Til the Cows Come Home

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;
const int maxn = 2005;

vector<pair<int ,int > >E[maxn];
int d[maxn];
int n,m,s,t,x,y,z;

void init(){
for(int i = 0;i < maxn;i++){
E[i].clear();
d[i] = 1e9;
}
}

int main(){
while(~scanf("%d%d",&m,&n)){
init();
while(m--){
scanf("%d%d%d",&x,&y,&z);
E[x].push_back(make_pair(y,z));
E[y].push_back(make_pair(x,z));
}
priority_queue<pair<int,int> >Q;
Q.push(make_pair(-d
,n));
d
= 0;
while(!Q.empty()){
int now = Q.top().second;
Q.pop();
for(int i = 0;i < E[now].size();i++){
int v = E[now][i].first;
if(d[v]>d[now]+E[now][i].second){
d[v] = d[now]+E[now][i].second;
Q.push(make_pair(-d[v],v));
}
}
}
printf("%d\n",d[1]);
}
return 0;
}