View Code of Problem 51

#include<stdio.h>
int main()
{
	int sum = 0, n;
	int a[10][10];
	scanf("%d", &n);
	for (int i = 0; i < n; ++i)
		for (int j = 0; j < n; ++j)
			scanf("%d", &a[i][j]);

	for (int i = 0; i < n; ++i)
		for (int j = 0; j < n; ++j)
			if (i >= j)
				sum += a[i][j];
		
	printf("%d", sum);
}