View Code of Problem 51

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