View Code of Problem 51

#include <stdio.h>
int main()
{
	int n;
	int a[15][15];
	scanf ("%d", &n);
	int sum = 0;
	for (int i=0; i<n ; i++)
	{
		for (int j=0; j<n; j++)
		{
			int x;
			scanf ("%d", &x);
			if (i >= j)
				sum += x;
		}
	}
	printf ("%d\n", sum);
	return 0;
}