递归变递推，DP

#include <bits/stdc++.h>#include<algorithm>using namespace std;#define MAX 101int D[MAX][MAX];int n;int *maxSum;int main(){int i,j;cin>>n;for(i=1;i<=n;i++)    for(j=1;j<=i;j++)       cin>>D[i][j];       maxSum=D[n];//maxSum  point at di n hang        for(int i=n-1;i>=1;i--)        for(int j=1;j<=i;++j)           maxSum[j]=              max(maxSum[j],maxSum[j+1])+D[i][j];  cout<<maxSum[1]<<endl;    }