SDUT 1730 数字三角形问题

#include<iostream>
#include<cstring>

using namespace std;

int main()
{
int n, i, j, a[102][102];
cin >> n;
memset(a, 0, sizeof(a));
for (i=1; i<=n; i++)
for (j=1; j<=i; j++)
cin >> a[i][j];
for (i=n; 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;
}