求大佬帮忙看下where挂了

#include<bits/stdc++.h>
using namespace std;
#define maxb 210000
#define maxd 15000
#define INTM  2147400000
int n,m,s,t;
struct BBB{
    int V,N,W;
}bian[maxb];
int Head[maxd],out=0;
void ADD(int u0,int v0,int w0)
{
    bian[out].N=Head[u0];bian[out].W=w0;bian[out].V=v0;Head[u0]=out;out++;
    bian[out].N=Head[v0];bian[out].W=0;bian[out].V=u0;Head[v0]=out;out++;
}
int DIS[maxd],q[maxd],tou=1,wei=1;
bool BF()
{
    for(int i=0;i<maxd;++i){DIS[i]=-1;}
    tou=1;wei=1;
    q[1]=s;DIS[s]=0;
    while(tou<=wei)
    {
        int _u=q[tou];tou++;
        for(int i=Head[_u];i!=-1;i=bian[i].N)
        {
            int _v=bian[i].V,_w=bian[i].W;
            if(DIS[_v]==-1&&_w)
            {
                wei++;q[wei]=_v;
                DIS[_v]=DIS[_u]+1;//cout<<"!!!";
            }
        }
    }
    return DIS[t]^(-1);
}

int DF(int curd,int liu)
{
    if(!(curd^t))return liu;
    int used=0;
    for(int i=Head[curd];i!=-1;i=bian[i].N)
    {
        int _V=bian[i].V,_W=bian[i].W;
        if(DIS[_V]=DIS[curd]+1&&_W)
        {
            int k=DF(_V,min(liu-used,_W));
            used+=k;
            bian[i^1].W+=k;
            bian[i].W-=k;
            if(used==liu)break;
        }
    }
    if(used==0)DIS[curd]=-1;
//  cout<<"  "<<used<<"  ";
    return used;
}
int main()
{
    scanf("%d%d%d%d",&n,&m,&s,&t);
    for(int i=1;i<=maxd;++i)Head[i]=-1;
    int u,v,w;
    for(int i=0;i<m;++i)
    {
        scanf("%d%d%d",&u,&v,&w);
        ADD(u,v,w);
    }//cout<<"~";
    long long ans=0;
    while(BF())
    {//cout<<"!";
        ans+=DF(s,INTM);//cout<<"@";
    }//cout<<"#";
    printf("%lld",ans);
    return 0;
}