求大神指教7/8/9点迷之re

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
using namespace std;
int s[4005],rdu[4005],head[4005],stop[4005],lo[4005],loi=0,cnt=0;
struct node
{
    int next,to;
}edge[1035000];
inline void add(int u,int g)  
{
    edge[++cnt].to = g;
    edge[cnt].next = head[u];
    head[u] = cnt;
}
bool b[4005],v[4005];
int main()
{
    register int i,j,k,m,n,u,top,x;
    memset(edge,0,sizeof(edge));
    memset(head,0,sizeof(head));
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;++i)
    {
        scanf("%d",&s[i]);
        memset(v,0,sizeof(v));
        for(j=0;j<s[i];++j)
        {
            scanf("%d",&u);
            stop[j]=u;
            v[u]=1;
        }
        for(k=0;k<s[i];++k)
        {
            for(j=stop[0]+1;j<stop[s[i]-1];++j)
            {
                if(!v[j])
                {
                    add(stop[k],j);
                    rdu[j]++;//Èë¶È 
                }
            }
        }
    }
    x=0;
    top=n;
    while(top>0)
    {
        x++;
        for(j=1;j<=n;++j)
        {
            if(!rdu[j])
            {
                top--;
                rdu[j]=-9;
                for(i=head[j];i;i=edge[i].next)
                {
                    if(rdu[edge[i].to]>0) rdu[edge[i].to]--;
                    if(!rdu[edge[i].to])
                    {
                        lo[++loi]=edge[i].to;//ÒÔ±ãºóÃæÈÃËü±ä»Ø0 
                        rdu[edge[i].to]=-4;
                    }
                }
            }
        }
        for(i=1;i<=loi;++i)
        {
            rdu[lo[i]]=0;
        }
        loi=0;
    }
    cout<<x;
    return 0;
}