View Code of Problem 51

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