View Code of Problem 51

#include<bits/stdc++.h>
using namespace std;

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