题目：https://www.luogu.com.cn/problem/P1216 //还需理解
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
int r; int num[1005][1005];
int f[1005][1005];
int dfs(int n, int m) {
if (n > r || m < 1 || m > r)
return 0;
if (f[n][m] != -1)
return f[n][m];
return f[n][m] = max(dfs(n + 1, m), dfs(n + 1, m + 1)) + num[n][m];
}
int main()
{
cin>>r;
memset(f, -1, sizeof(f));
for(int i = 1;i <= r;i++)
{
for(int j = 1;j <= i;j++)
{
cin>>num[i][j];
}
}
cout << dfs(1,1) << "\n";
return 0;
}