HDU 4280 Island Transport (the largest network Stream)

Question address: http://acm.hdu.edu.cn/showproblem.php? Pid = 1, 4280

This question is a pure largest stream template question .. It is the time of the card .. Fortunately, I will use the isap algorithm .. However, the pitfall is always WA, and the final input is optimized... (I just changed the input ..) I do not know why .. Please kindly read this blog's great god to enlighten me ..

The Code is as follows:

#include 
 
  #include 
  
   #include 
   
    #include 
    
     #include using namespace std;int head[210000], s, t, nv, maxint=0x3f3f3f3f, cnt;int cur[210000], pre[210000], q[5000000], d[210000], num[210000];struct node{    int u, v, cap, next;}edge[11000000];void add(int u, int v, int cap){    edge[cnt].v=v;    edge[cnt].cap=cap;    edge[cnt].next=head[u];    head[u]=cnt++;    edge[cnt].v=u;    edge[cnt].cap=cap;    edge[cnt].next=head[v];    head[v]=cnt++;}void bfs(){    memset(num,0,sizeof(num));    memset(d,-1,sizeof(d));    int f1=0, f2=0, i;    q[f1++]=t;    d[t]=0;    num[0]=1;    while(f1>=f2)    {        int u=q[f2++];        for(i=head[u];i!=-1;i=edge[i].next)        {            int v=edge[i].v;            if(d[v]==-1)            {                d[v]=d[u]+1;                num[d[v]]++;                q[f1++]=v;            }        }    }}void isap(){    memcpy(cur,head,sizeof(cur));    int flow=0, u=pre[s]=s, i;    bfs();    while(d[s]
     
      edge[cur[i]].cap)                {                    f=edge[cur[i]].cap;                    pos=i;                }            }            for(i=s;i!=t;i=edge[cur[i]].v)            {                edge[cur[i]].cap-=f;                edge[cur[i]^1].cap+=f;            }            flow+=f;            //printf("--");            u=pos;        }        for(i=cur[u];i!=-1;i=edge[i].next)        {            if(d[edge[i].v]+1==d[u]&&edge[i].cap)            {                break;            }        }        if(i!=-1)        {            cur[u]=i;            pre[edge[i].v]=u;            u=edge[i].v;        }        else        {            if(--num[d[u]]==0) break;            int mind=nv+1;            for(i=head[u];i!=-1;i=edge[i].next)            {                if(mind>d[edge[i].v]&&edge[i].cap)                {                    mind=d[edge[i].v];                    cur[u]=i;                }            }            d[u]=mind+1;            num[d[u]]++;            u=pre[u];        }    }    printf("%d\n",flow);}int read(){    int flag = 0, x = 0;    char ch = ' ';    while(ch != '-' && (ch > '9' || ch < '0')) ch = getchar();    if(ch == '-') flag = 1, ch = getchar();    while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();    return flag ? -x : x;}int main(){    int T, n, m, i, j, a, b, c, x, y, min1, max1;    scanf("%d",&T);    while(T--)    {        memset(head,-1,sizeof(head));        cnt=0;        n=read();m=read();        min1=999999;        max1=-999999;        for(i=1;i<=n;i++)        {            x=read();y=read();            if(min1>x)            {                min1=x;                s=i;            }           if(max1