题解：

#include<bits/stdc++.h>
using namespace std;
const int N=2010;
int b[N][N];
int n,m;
void insert(int x1,int y1,int x2,int y2){
    b[x1][y1]++;
    b[x2+1][y1]--;
    b[x1][y2+1]--;
    b[x2+1][y2+1]++;
}
int main(){
    scanf("%d%d",&n,&m);
    while(m--){
        int x1,y1,x2,y2;
        scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
        insert(x1,y1,x2,y2);
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            b[i][j]+=b[i-1][j]+b[i][j-1]-b[i-1][j-1];
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cout<<b[i][j]%2;
        }
        cout<<endl;
    }
    return 0;
}

有定

https://www.bilibili.com/video/BV1GJ411x7h7/