HDU-1839 Delay Constrained Maximum Capacity Path 最短路

#include "stdio.h"
#include "string.h"
#include "vector"
#include "queue"
#include "algorithm"
using namespace std;
const int maxn = 10005;
const int inf = 1<<29;
int n,m,T,pos;
int s[maxn*5];
int dis[maxn];
bool vis[maxn];
struct node
{
int v,cap,t,next;
}edge[maxn*10];
int head[maxn];
void add( int a,int b,int c,int d )
{
edge[++pos].v = b; edge[pos].cap = c; edge[pos].t = d;
edge[pos].next = head[a];
head[a] = pos;
}

typedef pair<int,int>pii;
bool Dijkstra( int s,int Cap )
{
for( int i = 1; i <= n; i ++ )
dis[i] = inf;
memset( vis,0,sizeof(vis) );
priority_queue<pii,vector<pii>,greater<pii> >que;
dis[s] = 0;
que.push( make_pair(dis[s],s) );
while( !que.empty() )
{
pii u = que.top(); que.pop();
int x = u.second;
vis[x] = true;
if( dis[x] > T ) return false;
if( x == n ) return dis[x];
for( int i = head[x]; i != -1; i = edge[i].next )
{
node v = edge[i];
if( v.cap < Cap || vis[v.v] ) continue;
if( dis[v.v] > dis[x] + v.t )
{
dis[v.v] = dis[x] + v.t;
que.push( make_pair(dis[v.v],v.v) );
}
}
}
return false;
}
void init()
{
pos = 0;
for( int i = 1; i <= n; i ++ )
head[i] = -1;
}
int main()
{
//freopen( "data.txt","r",stdin );
int t,a,b,c,d;
scanf("%d",&t);
while( t-- )
{
scanf("%d%d%d",&n,&m,&T);
init();
for( int i = 0; i < m; i ++ )
{
scanf("%d%d%d%d",&a,&b,&c,&d);
add(a,b,c,d);
add(b,a,c,d);
s[i] = c;
}
sort(s,s+m);
int ld = 0,rd = 0,mid;
for( int i = 1; i < m; i ++ )
{
if( s[i] != s[i-1] )
s[++rd] = s[i];
}
while( ld <= rd )
{
mid = (ld+rd)>>1;
if( Dijkstra( 1,s[mid] ) )
{
ld = mid+1;
}
else rd = mid-1;
}
printf("%d\n",s[rd]);
}
return 0;
}