View Code of Problem 51

#include<stdio.h>

int main()
{
	int n, a[15][15], i, j, sum = 0;
	while(scanf("%d",&n) != EOF)
	{
		for(i = 1; i <= n; i++)
		{
			for(j = 1; j <= n; j++)
				scanf("%d", &a[i][j]);
		}
		for(i = 1; i <= n; i++)
		{
			for(j = 1; j <= i; j++)
			sum += a[i][j];
		}
		printf("%d\n", sum);

	}
	return 0;
}