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diff --git a/challenge-092/jcrosswh/perl/ch-1.pl b/challenge-092/jcrosswh/perl/ch-1.pl new file mode 100644 index 0000000000..f16596b367 --- /dev/null +++ b/challenge-092/jcrosswh/perl/ch-1.pl @@ -0,0 +1,102 @@ +#!/usr/bin/env perl + +use strict; +use warnings; + +=head1 NAME + +PWC 092 Challenge 1 + +=head1 SYNOPSIS + + $ ch-1.pl egg add + 1 + + $ ch-1.pl foo bar + 0 + +=head1 DESCRIPTION + +Given two strings $A and $B, this script will check to see if the given strings +are isomorphic. It will print 1 if they are otherwise 0. + +=head1 SOLUTION + +This solution assumes that if the number of characters in each string is equal, +then the two strings are isomorphic. This script works by going though all +characters, assuming case sensetivity, and determining in each inputed string +the number of times that character appears. Internally the script maintains a +hash that keys on the number of times a character appears, and that key maps to +an array that captures which characters appeared that number of times. + +Once all combinations are determined, the script will go through key values 1-> +the maximum number of characters found, and examining the sizes of the arrays +for both strings for the given key. If at any time these arrays don't match in +size, then the script will print 0 and exit, otherwise we'll complete the +examination and print 1. + +For example, for the given strings 'egg' and 'add', the two hashes will look +like this: + +egg: (0, ["A" .. "Z", "a" .. "d", "f", "h" .. "z"], 1, ["e"], 2, ["g"]) +add: (0, ["A" .. "Z", "b", "c", "e" .. "z"], 1, ["a"], 2, ["d"]) + +Ignoring the non-appearing characters (0), we see that the size of the '1' array +is 1 for both strings, and the size of the '2' array is 1 for both strings, +therefore, 'egg' and 'add' are isomorphic. + +=head1 AUTHORS + +Joel Crosswhite E<lt>joel.crosswhite@ix.netcom.comE<gt> + +=cut + +my $first_string = $ARGV[0]; +my $second_string = $ARGV[1]; +if ((!defined($first_string) || $first_string !~ m/^[a-zA-Z]*$/) + || (!defined($second_string) || $second_string !~ m/^[a-zA-Z]*$/)) { + print "Usage: ch-1.pl <string> <string>\n"; + exit 1; +} + +my (%char_map_first_string, %char_map_second_string); +my $max_chars_found = 0; +foreach my $starting_char ('A', 'a') { + + foreach my $char ($starting_char..'z') { + + find_number_of_characters($char, $first_string, + \%char_map_first_string, \$max_chars_found); + find_number_of_characters($char, $second_string, + \%char_map_second_string, \$max_chars_found); + } +} + +foreach my $key (1..$max_chars_found) { + + if (size_of_hash_array($char_map_first_string{$key}) + != size_of_hash_array($char_map_second_string{$key})) { + + print 0 . "\n"; + exit 0; + } +} + +print 1 . "\n"; +exit 0; + +sub find_number_of_characters { + my ($char, $string, $char_map, $max_chars_found) = @_; + + my @chars_found = ($string =~ /$char/g); + push(@{$char_map->{scalar(@chars_found)}}, $char); + $$max_chars_found = (scalar(@chars_found) > $$max_chars_found) + ? scalar(@chars_found) + : $$max_chars_found; +} + +sub size_of_hash_array { + my ($array) = @_; + + return defined($array) ? scalar(@{$array}) : 0; +}
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