开始接触dp啦，希望越来越好

#include <iostream>
#include <cstring>
using namespace std;

const int N = 510;
const int INF = 0x3f3f3f3f;
int dp[N][N];
int a[N][N];

int main(){
    int n;
    cin >> n;
    memset(dp, -INF, sizeof dp);

    for (int i = 1; i <= n; i ++ ){
        for (int j = 1; j <= i; j ++ ){
            cin >> a[i][j];
        }
    }

    dp[1][1] = a[1][1];

    for(int i = 2; i <= n; i++){
        for (int j = 1; j <= i; j ++ ){
            dp[i][j] = a[i][j] + max(dp[i-1][j], dp[i-1][j-1]);
        }
    }

    int res = -INF;
    for (int i = 1; i <= n; i ++ ) res = max(res, dp[n][i]);
    cout << res;

    return 0;
}