View Code of Problem 51

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