# include<stdio.h>
# include<stdlib.h>
# include<conio.h>
int main (void)
{ int i,TRUE;
  TRUE=1;
  printf ("Enter:\n");
   while (TRUE)
   {
      scanf ("%i", &i);
        if ( i == 999 )
         break;
      else
      printf ("the word you input is %i\n", i);

   }
   printf ("end of input!");
   getch();
   return 0;
}

注意下标范围！