View Code of Problem 30

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