View Code of Problem 51

#include <iostream>
using namespace std;

int main()
{
	int n, sum = 0;
	int a[10][10];
	cin >> n;
	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			cin >> a[i][j];
	for (int i = 0; i < n; i++)
		for (int j = 0; j <= i; j++)
			sum += a[i][j];
	cout << sum << endl;
	return 0;
}