POJ_2387_Til the Cows Come Home（USACO 2004 November）_最短路径

#include<iostream>
#include<cstdio>
#include<queue>
#include<vector>
#include<cstring>
using namespace std;
const int N =1050;
int t,n;
vector <int> E
,W
;
int d
;
bool vd
;
void spfa(int s)
{
memset(d,0x7f,sizeof(d));
memset(vd,false,sizeof(vd));
queue <int> q;
q.push(s);
vd[s]=true;
d[s]=0;
while (q.size())
{
int u=q.front();
vd[u]=false;
q.pop();
for (int i=0;i<E[u].size();i++)
{
int v=E[u][i];
int w=W[u][i];
if (d[u]+w<d[v])
{
d[v]=w+d[u];
if (vd[v]==false)
{
q.push(v);
vd[v]=true;
}
}
}
}
}
int main()
{
int a,b,c;
scanf ("%d%d",&t,&n);
for (int i=1;i<=t;i++)
{
scanf ("%d%d%d",&a,&b,&c);//储存为双向边
E[a].push_back(b);
E[b].push_back(a);
W[a].push_back(c);
W[b].push_back(c);
}
spfa (1);
printf ("%d\n",d
);
return 0;
}