poj - 1163 The Triangle

#include <stdio.h>
int a[100][100];
int max(int a,int b)
{
return a>b ?a :b ;
}
int main()
{
int n,i,j,ans;
while(~scanf("%d",&n))
{
for(i = 0; i < n; i++)
for(j = 0; j <= i; j++)
scanf("%d",&a[i][j]);
for(i = 1; i < n; i++)
a[i][0] += a[i-1][0],
a[i][i] += a[i-1][i-1];
for(i = 2; i < n-1; i++)
for(j = 1; j < i; j++)
a[i][j] += max(a[i-1][j-1],a[i-1][j]);
ans = max(a[n-1][0],a[n-1][n-1]);
for(j = 1; j < n-1; j++)
{
a[n-1][j] += max(a[n-2][j-1],a[n-2][j]);
ans = max(ans,a[n-1][j]);
}
printf("%d\n",ans);
}
return 0;
}