백준 1749 점수따먹기 혼내주기

 

 

#include <iostream>
using namespace std;

int arr[201][201];

int main(){
    int n, m;
    cin >> n >> m;
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            cin >> arr[i][j];

    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            arr[i][j] = arr[i][j] + arr[i-1][j] + arr[i][j-1] - arr[i-1][j-1];

    int ans = -1e9;
    for(int x1 = 1; x1 <= n; ++x1){
        for(int y1 = 1; y1 <= m; ++y1){
            for(int x2 = x1; x2 <= n; ++x2){
                for(int y2 = y1; y2 <= m; ++y2){
                    ans = max(ans, arr[x2][y2] - arr[x1-1][y2] - arr[x2][y1-1] + arr[x1-1][y1-1]);
                }
            }
        }
    }
    cout << ans;
}