大牛帮忙看一下我做的水题代码（编译正确，程序崩溃）

//chore
#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<cstdlib>
#include<cmath>
#include<ctime>
#include<vector>
#define maxn 10001
using namespace std;
int n,ans;
struct node{
    int xh;//ÐòºÅ 
    int pre[maxn];//Ç°Çý 
    int in;//Èë¶È 
    int t;//ÓÃʱ 
}a[maxn];
void fun(){
    for(int i=1;i<=n;i++)
      for(int j=1;j<n;j++){
          if(a[i].in>a[j].in){
            swap(a[j],a[i]);
          }
          if(a[i].in&&a[i].in==a[j].in)
            for(int k=1;k<=a[i].in;k++)
                while(a[i].pre[k]==a[j].pre[k])
                  if(a[i].t>a[j].t) a[j].t=0;
      }
    for(int i=1;i<=n;i++){
        ans+=a[i].t;
        //cout<<a[i].xh<<"->";
    }
    return;
}
int main(){
    freopen("chore.in","r",stdin);
    freopen("chore.out","w",stdout);
    cin>>n;
    for(int i=1;i<=n;i++){
        struct node a[i];
        int q=0;cin>>a[i].xh;
        cin>>a[i].t;
        for(int j=1;;j++){
            cin>>a[i].pre[j];
            while(a[i].pre[j]==0){a[i].in=q;break;}
            q++;
        }
    }
    fun();
    printf("%d\n",ans);
    return 0;
}