POJ-1797 Heavy Transportation(dijkstra)

//路径上的最短边要最长,求该边  读错题WA1
#include <cstdio>
#include <algorithm>
#include <queue>
#include <cstring>
#include <cmath>
using namespace std;
typedef pair<int,int> PII;
const int MAXN=1222;
const int MAXM=MAXN*MAXN/2;
const int INF=0x3f3f3f3f;
int head[MAXN],to[MAXM<<1],ne[MAXM<<1],wt[MAXM<<1],n,m,dist[MAXN],ecnt,T;
void init()
{
ecnt=0;
memset(head,0,sizeof(head));
}
void addedge(int a,int b,int c)
{
ne[++ecnt]=head[a];
head[a]=ecnt;
to[ecnt]=b;
wt[ecnt]=c;
}
int vis[MAXN];
priority_queue<PII> pq;
int dijkstra(int s,int t)//s为源点，t为终点
{
for(int i=1;i<=n;i++)
dist[i]=0,vis[i]=0;
dist[s]=INF;
pq.push(PII(INF,s));
while(!pq.empty())
{
int fr=pq.top().second;
pq.pop();
if(vis[fr])continue;
vis[fr]=1;
for(int k=head[fr];k;k=ne[k])
{
int v=to[k];
if(dist[v]<min(dist[fr],wt[k]))
{
dist[v]=min(dist[fr],wt[k]);
pq.push(PII(dist[v],v));
}
}
}
return dist[t];
}
int main()
{
scanf("%d",&T);
for(int kase=1;kase<=T;kase++)
{
int ta,tb,tc;
scanf("%d%d",&n,&m);
init();
for(int i=1;i<=m;i++)
{
scanf("%d%d%d",&ta,&tb,&tc);
addedge(ta,tb,tc);
addedge(tb,ta,tc);
}
printf("Scenario #%d:\n%d\n\n",kase,dijkstra(1,n));
}
return 0;
}