HDU 1839 Delay Constrained Maximum Capacity Path(二分+最短路）

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <ctype.h>
#include <queue>
#include <map>
#include<algorithm>
using namespace std;
const int INF=0x3f3f3f3f;
int head[11000], vis[11000], d[11000], cnt, n;
struct node1
{
int u, v, w, cost;
}bian[50002];
struct node
{
int u, v, w, next, cost;
}edge[1000000];
void add(int u, int v, int w, int cost)
{
edge[cnt].v=v;
edge[cnt].w=w;
edge[cnt].cost=cost;
edge[cnt].next=head[u];
head[u]=cnt++;
}
int spfa()
{
memset(d,INF,sizeof(d));
memset(vis,0,sizeof(vis));
d[1]=0;
deque<int>q;
q.push_back(1);
while(!q.empty())
{
int u=q.front();
q.pop_front();
vis[u]=0;
for(int i=head[u];i!=-1;i=edge[i].next)
{
int v=edge[i].v;
if(d[v]>d[u]+edge[i].cost)
{
d[v]=d[u]+edge[i].cost;
if(!vis[v])
{
vis[v]=1;
if(!q.empty()&&d[v]<d[q.front()])
{
q.push_front(v);
}
else
{
q.push_back(v);
}
}
}
}
}
}
int main()
{
int t, i, m, time, max1;
scanf("%d",&t);
while(t--)
{
scanf("%d%d%d",&n,&m,&time);
max1=-1;
for(i=0;i<m;i++)
{
scanf("%d%d%d%d",&bian[i].u,&bian[i].v,&bian[i].w,&bian[i].cost);
if(max1<bian[i].w)
max1=bian[i].w;
}
__int64 low=0, high=max1, mid, ans=-1;
while(low<=high)
{
mid=(low+high)/2;
memset(head,-1,sizeof(head));
cnt=0;
for(i=0;i<m;i++)
{
if(bian[i].w>=mid)
{
add(bian[i].u,bian[i].v,bian[i].w,bian[i].cost);
add(bian[i].v,bian[i].u,bian[i].w,bian[i].cost);
}
}
spfa();
if(d
<=time)
{
low=mid+1;
ans=mid;
}
else
{
high=mid-1;
}
}
printf("%d\n",ans);
}
return 0;
}