View Code of Problem 51

#include<stdio.h>
#include<stdlib.h>
int main()
{
int n,i,j;
int sum=0;
  scanf("%d",&n);
  int a[n+1][n+1];
  for(i=0;i<n;i++)
    for(j=0;j<n;j++)
      scanf("%d",&a[i][j]); 
  for(i=0;i<n;i++)
   for(j=0;j<=i;j++)
      sum+=a[i][j];
   printf("%d",sum);
   return 0;
 
}