最简单的“数塔”问题

#include <iostream>
#define maxn 100
using namespace std;
int max(int a,int b)
{
return (a>b?a:b);
}
int main()
{
int a[maxn+1][maxn+1],i,j,n;
cin >>n;
for (i=1;i<=n;i++)for (j=1;j<=i;j++) cin >>a[i][j];
for (i=n-1;i>=1;i--)for (j=1;j<=i;j++) a[i][j]+=max(a[i+1][j],a[i+1][j+1]);
cout <<a[1][1]<<endl;
return 0;
}