问题标题: 酷町堂：这是什么编译错误？？

#include<iostream>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<sstream>
#include<algorithm>
#include<queue>
#include<vector>
#include<string>
#include<stack>
#include<cstdlib>
int a[1001][1001],b[1001][1001],c[1001],d[1001];
int n,m,x,y;
int main(){
    memset(a,0,sizeof(a));
    memset(b,0,sizeof(b));
    memset(c,0,sizeof(c));
    memset(d,0,sizeof(d));
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>x>>y;
        a[x][y]=1;
        b[y][x]=1;
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            for(int k=1;k<=n;k++){
                if((a[i][j]==1)&&(a[j][k]==1)&&(i!=k)){
                    a[i][k]=1;
                    b[k][i]=1;
                }
                if((b[i][j]==1)&&(b[j][k]==1)&&(i!=k)){
                    b[i][k]=1;
                    a[k][i]=1;
                }
            }
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(a[i][j]==1) c[i]++;
            if(b[i][j]==1) d[i]++;
        }
    }
    int s=0;
    for(int i=1;i<=n;i++){
        if((c[i]>=(n+1)/2)||(d[i]>=(n+1)/2)){
            s++;
        }
    }
    cout<<s<<endl;
    return 0;
}