#include<stdio.h>

main()
{
int a, sum=0;
scanf("%d",&a);
if(a<0&&a>=-10000)
{
  int i;
  for(i=a;i<=1;i++)
  {
    sum=sum +i;

}
printf("%d",sum);
}

else if( a>=0&&a<=10000)
{
     int i;
     for(i=1;i<=a;i++)
     {
      sum=sum +i;
      }
     printf("%d",sum);

}

}

when a = 0, the answer is 1, not 0

Edited by author 12.10.2012 23:50

I have executed the program and when I input 0 the result is also 0. But still they are not accepted