动态规划

#include <iostream>
#include <algorithm>
using namespace std;
int main() {
    int n;
    cin >> n;
    int ** sum = new int*[n];
    sum[0] = new int;
    cin >> sum[0][0]; 
    for (int i = 1; i < n; i++) {
        sum[i] = new int[i+1];
        for (int j = 0; j < i+1; j++) {
            int now;
            cin >> now;
            if (j == i) {
                sum[i][j] = sum[i-1][j-1] + now;
            } else if (j == 0) {
                sum[i][j] = sum[i-1][j] + now;
            } else {
                sum[i][j] = max(sum[i-1][j], sum[i-1][j-1]) + now;
            }
        }
    }
    int ans = 0;
    for (int i = 0; i < n; i++) {
        if (ans < sum[n-1][i])
            ans = sum[n-1][i];
    }
    cout << ans << endl;
    return 0;
}