题目描述

样例

#include <iostream>
using namespace std;

const int N = 505;
int v[N], f[N];

int main() {
    int n, ans = -0x3f3f3f3f;
    cin >> n;
    fill(f, f + n + 1, -0x3f3f3f3f);
    fill(v, v + n + 1, -0x3f3f3f3f);
    f[1] = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) cin >> v[j];
        for (int j = i; j >= 1; j--) f[j] = max(f[j-1], f[j]) + v[j];
    }
    for (int i = 1; i <= n; i++) ans = max(f[i], ans);
    cout << ans << endl;
    return 0;
}