#!/usr/bin/perl

use strict;
use warnings;

Test();

sub hasSameChars
{
  # Make sure each argument has the same type and same length.
  @_ > 1 or return 0;   # Require at least 2 arguments

  # Check if arguments are of the same length.

  my $THISLEN = -2;  # Current argument's length
  my $PREVLEN = -2;  # Previous argument's length
  foreach (@_)
  {
    $THISLEN = (defined $_) ? length($_) : -1;
    if ($PREVLEN > -2) { $PREVLEN == $THISLEN or return 0; }    
    $PREVLEN = $THISLEN;
  }

  # Okay, at this point, we know that all arguments are
  # the same type and same length. If they are all undefined,
  # then $THISLEN will be -1 or if they are all empty strings, then
  # $THISLEN will be zero, so we can exit right here in that case:
  $THISLEN < 1 and return 1;

  # We end up here if all arguments are defined, and all are the same length.

  # Check if arguments have the same makeup:

  my $SAMPLE = join('', sort(split(//, shift)));
  foreach (@_)
  {
    join('', sort(split(//, $_))) eq $SAMPLE or return 0;
  }

  return 1;
}

sub Test
{
  my $ERRORS = 0;

  # TESTING TRUE:
  hasSameChars("Hello World!", "Hello World!")                 == 1 or $ERRORS++;
  hasSameChars("Hello World!", "Hdll!ooreWl ")                 == 1 or $ERRORS++;
  hasSameChars("Hello World!", "Hdll!ooreWl ", "Hlde! Wlloor") == 1 or $ERRORS++;
  hasSameChars("FALLEN", "LENFAL", "ELFALN")                   == 1 or $ERRORS++;
  hasSameChars(undef, undef, undef)                            == 1 or $ERRORS++;
  hasSameChars('', '', '', '')                                 == 1 or $ERRORS++;
  hasSameChars('A', 'A', 'A', 'A')                             == 1 or $ERRORS++;
  hasSameChars("\r\n\t\0\0\1", "\0\1\t\0\n\r", "\n\1\r\t\0\0") == 1 or $ERRORS++;
  hasSameChars('ABB', 'BBA', 'BAB', 'BBA')                     == 1 or $ERRORS++;
  hasSameChars('   ', '   ', '   ', '   ')                     == 1 or $ERRORS++;
  hasSameChars("ABC", "CAB", "BAC", "BCA", "ACB", "ABC")       == 1 or $ERRORS++;

  # TESTING FALSE:
  hasSameChars("\r\n\t\0\1\2", "\0\2\t\1\n\r", "\t\t\r\1\2\n") == 0 or $ERRORS++;
  hasSameChars("Hello World!", "Hdll!ooreWl ", "Hlde! Wlloo")  == 0 or $ERRORS++;
  hasSameChars("Hello World!", "Hdll!ooreWl")                  == 0 or $ERRORS++;
  hasSameChars("ABC", "C_B", "BAC", "BCA", "ACB", "ABC")       == 0 or $ERRORS++;
  hasSameChars("ALLEN", "ELLEN", "HALLEN", "HELLEN")           == 0 or $ERRORS++;
  hasSameChars("FALLEN", "Lenfal", "ELFALN")                   == 0 or $ERRORS++;
  hasSameChars("FALLEN", "FALLEN ")                            == 0 or $ERRORS++;
  hasSameChars(undef, "FALLEN", "FALLEN")                      == 0 or $ERRORS++;
  hasSameChars("FALLEN", undef, "FALLEN")                      == 0 or $ERRORS++;
  hasSameChars("FALLEN", "FALLEN", undef)                      == 0 or $ERRORS++;
  hasSameChars('', undef, undef)                               == 0 or $ERRORS++;
  hasSameChars('ABB', 'ABA', 'BAA', 'BAA')                     == 0 or $ERRORS++;
  hasSameChars('   ', '   ', '   ', "\t")                      == 0 or $ERRORS++;

  print "\n\n ERRORS = $ERRORS \n\n";
}