View Code of Problem 51

#include<stdio.h>
int main()
{
	int n,i,j;
	int a[100][100],sum=0;
	scanf("%d",&n);
	if(n>0)
	{
		for(i=0;i<n;++i)
		{
			for(j=0;j<n;++j)
			{
				scanf("%d",&a[i][j]);
			}
		}//½ÓÊܶþάÊý×é ¼´¾ØÕó 
		for(i=0;i<n;++i)
		{
			for(j=0;j<=i;++j)
			{
				sum = sum + a[i][j];
			}
		}
		printf("%d",sum);
		return 0;
		
	}
 }