Adding solution for week 92, challenge 1.

1 files changed, 102 insertions, 0 deletions

diff --git a/challenge-092/jcrosswh/perl/ch-1.pl b/challenge-092/jcrosswh/perl/ch-1.pl
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+++ b/challenge-092/jcrosswh/perl/ch-1.pl
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+#!/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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