View Code of Problem 51

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

}