/*********************************************************
 * From C PROGRAMMING: A MODERN APPROACH, Second Edition *
 * By K. N. King                                         *
 * Copyright (c) 2008, 1996 W. W. Norton & Company, Inc. *
 * All rights reserved.                                  *
 * This program may be freely distributed for class use, *
 * provided that this copyright notice is retained.      *
 *********************************************************/

/* repdigit.c (Chapter 8, page 166) */
/* Checks numbers for repeated digits */

#include <stdio.h>
#include <limits.h>
/* We assume here that 0 represents FALSE, and 1 represents TRUE */
#define TRUE 1
#define FALSE 0

int main(void)
{
  /* It is sufficient to initialize just one element of the array, since
     the remaining elements of the array are given the value 0 by default.
     It is illegal for an initializer to be empty. Also, it is illegal for 
     an initializer to be longer than the array it initializes. If a complete 
     initializer is present, it determines the length of the array, so 
     the length of the array may be left unspecified explicitly.
  */
  int digit_seen[10] = {FALSE};
  int digit;
  long int n;
  /* For your information, long int has at least 32 bits in size, but on a computer
  with 64 bits CPU   long int has 64 bits. In  limits.h  header file, a macro 
  LONG_MAX defines the maximum value for a long int.   */
  printf("The value of LONG_MAX on this computer is %ld\n", LONG_MAX);  

  printf("Enter a number: ");
  scanf("%ld", &n);

  while (n > 0) {
    digit = n % 10;
    if (digit_seen[digit])
      break;
    digit_seen[digit] = TRUE;
    n = n / 10;
  }

  if (n > 0)
    printf("Repeated digit\n");
  else
    printf("No repeated digit\n");

  return 0;
}