> I don't know why I always get "wrong answer" for
submitting
> my pascal program, solving this problem. I'd be pleased
if
> someone will give me code, that solves it (I'm just
curious
> what is wrong in my program).
Here is my source : (C++)

#include <stdio.h>

int i;long sum=0;
int n;

void main()
 {
  scanf("%d",&n);
  if(n<1)
   for(i=1;i>=n;i--)
    sum+=i;
  else
   for(i=1;i<=n;i++)
    sum+=i;
  printf("%ld",sum);
 }