蒟蒻救助！！！

凭啥我的代码T了？？？！！！

#include<bits/stdc++.h>
#define MK 1500
using namespace std;
int n,m;
int s[MK][MK];
int flag[MK][MK];
int indegree[MK];
int mp[MK][MK];
int ans;

int add(int x,int y)
{
    if(mp[x][y]==1)
    {
        return 0;
    }
    mp[x][y] = 1;
    indegree[y]++;
    return 0;
}

int dis[MK];

int topsort()
{
    queue<int>qu;
    for(int i=1;i<=n;i++)
    {
        if(indegree[i]==0)
        {
            qu.push(i);
            dis[i] = 1;
            ans = 1;
        }
    }
    while(!qu.empty())
    {
        int f = qu.front();
        qu.pop();
        for(int i=1;i<=n;i++)
        {
            if(mp[f][i]==0)
            {
                continue;
            }
            int to = i;
            indegree[to]--;
            ans = max(dis[to],dis[f]+1);
            dis[to] = dis[f]+1;
            if(indegree[to]==0)
            {
                qu.push(to);
            }
        }
    }
    return 0;
}

signed main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int x;
        int y;
        scanf("%d",&x);
        for(int j=1;j<=x;j++)
        {
            scanf("%d",&y);
            s[i][j] = y;
            flag[i][y] = 1;
        }
        for(int j=1;j<=x;j++)
        {
            for(int k=s[i][1];k<=s[i][x];k++)
            {
                if(flag[i][k]==1)
                {
                    continue;
                }
                add(s[i][j],k);
            }
        }
    }
    topsort();
    printf("%d",ans);
    return 0;
}