递归变递推，DP

#include <bits/stdc++.h>
#include<algorithm>
using namespace std;
#define MAX 101
int 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;    
}