rt，暴力AC了，code：

#include <iostream>

#define maxn 1005

int n,m,a[maxn][maxn];

int main(){
    
    std::cin.tie(0)->sync_with_stdio(0);
    
    std::cin >> n >> m;
    for (int i = 1;i <= m;i++){
        
        int x1,y1,x2,y2;
        
        std::cin >> x1 >> y1 >> x2 >> y2;
        for (int j = x1;j <= x2;j++)
            for (int k = y1;k <= y2;k++)
                a[j][k]++;
        
    }
    for (int i = 1;i <= n;i++){
        
        for (int j = 1;j <= n;j++)
            std::cout << a[i][j] << ' ';
        std::cout << '\n';
        
    }
    
    return 0;
}

不要说1e9能过很正常，如果正是这样加大数据范围/改标签，记录