题解 | #小美的蛋糕切割#

枚举横着切还是竖着切，然后切多少，用二维前缀和加速即可。

#include<bits/stdc++.h>
#define int long long
#define double long double
#define x first
#define y second
using namespace std;
typedef long long LL;
typedef long long ll;
typedef pair<int, int> PII;
const int N = 3e5 + 10;
const int M = 1e3 + 10;
int mod = 1e9 + 7;
int a[M][M];
int ask(int x1, int y1, int x2, int y2) {
    return a[x2][y2] - a[x1 - 1][y2] - a[x2][y1 - 1] + a[x1 - 1][y1 - 1];
}

void solve() {
    int n;
    cin >> n;
    int m;
    cin >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
            a[i][j] += a[i - 1][j] + a[i][j - 1] - a[i - 1][j - 1];
        }
    }
    int minn = 1e18;
    for (int i = 1; i <= n;
            i++) minn = min(minn, abs(ask(1, 1, i, m) - ask(i + 1, 1, n, m)));
    for (int i = 1; i <= m;
            i++) minn = min(minn, abs(ask(1, 1, n, i) - ask(1, i + 1, n, m)));
    cout << minn << "\n";
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int _;
    _ = 1;
    //cin>>_;
    while (_--) {
        solve();
    }
}