View Code of Problem 51

#include<stdio.h>
#include <string.h>
#include <math.h>
int main(){
	int n;
	int a[100][100];
	int i,j;
	int sum;
	while(scanf("%d",&n)!=EOF){
		for(i=0;i<n;i++){
		  for(j=0;j<n;j++){
		  	scanf("%d",&a[i][j]);
		  }
		}
		sum=0;
		for(i=0;i<n;i++){
			for(j=0;j<=i;j++){
				sum +=a[i][j];
			}
		}
		printf("%d\n",sum);
	}
	return 0;
}