/* Programmed by Kurt Normark, April 2003 */

#include <stdio.h>

int is_palindrome_len(char *str, int lgt);

int is_palindrome(char *str){
  int lgt = strlen(str);
  return is_palindrome_len(str, lgt);
}

int is_palindrome_len(char *str, int lgt){
  int result;

  if (lgt >= 2)
   result = 
     str[0] == str[lgt-1] &&
     is_palindrome_len(str+1, lgt-2);
  else
    result = 1;

  return result;
}


int main(void) {

  char str[100];

  do{
    printf("Enter string: ");
    scanf("%s", str);

    if (strcmp(str,"exit") != 0){
      if (is_palindrome(str))
        printf("%s is a palindrome\n", str);
      else
        printf("%s is NOT a palindrome\n", str);
    }
  }
  while (strcmp(str,"exit") != 0);

  return 0;
}