View Code of Problem 51

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

	return 0;
}