perl anagram detection

Author: simula67

solutions/perl/anagram-detection.pl

@@ -0,0 +1,81 @@
+#!/usr/bin/perl -w
+use Data::Dumper;
+my %prime_map = (
+	'a' => 2,
+	'b' => 3,
+	'c' => 5,
+	'd' => 7,
+	'e' => 11,
+	'f' => 13,
+	'g' => 17,
+	'h' => 19,
+	'i' => 23,
+	'j' => 29,
+	'k' => 31,
+	'l' => 37,
+	'm' => 41,
+	'n' => 43,
+	'o' => 47,
+	'p' => 53,
+	'q' => 59,
+	'r' => 61,
+	's' => 67,
+	't' => 71,
+	'u' => 73,
+	'v' => 79,
+	'w' => 83,
+	'x' => 89,
+	'y' => 97,
+	'z' => 101,
+	'A' => 103,
+	'B' => 107,
+	'C' => 109,
+	'D' => 113,
+	'E' => 127,
+	'F' => 131,
+	'G' => 137,
+	'H' => 139,
+	'I' => 149,
+	'J' => 151,
+	'K' => 163,
+	'L' => 167,
+	'M' => 173,
+	'N' => 179,
+	'O' => 181,
+	'P' => 191,
+	'Q' => 193,
+	'R' => 197,
+	'S' => 199,
+	'T' => 211,
+	'U' => 223,
+	'V' => 227,
+	'W' => 229,
+	'X' => 233,
+	'Y' => 239,
+	'Z' => 241
+);
+sub compute_checkproduct {
+	(my $input_string) = @_;
+	my @characters = split '', $input_string;
+	my $checkproduct = 1;
+	foreach $character (@characters) {
+		$checkproduct *= $prime_map{$character};
+	}
+	$checkproduct;
+}
+sub detect_anagrams {
+	(my $haystack, my $needle) = @_;
+	my $found = 0, $needle_length = length($needle), $haystack_length = length($haystack);
+	return 0 if ($haystack_length < $needle_length );
+	my $needle_checkproduct = compute_checkproduct( $needle );
+	for( $i = 0; $i < (length($haystack) - length($needle)); $i++ ) {
+		my $haystack_slice = substr( $haystack, $i, length($needle) );
+		my $haystack_slice_checkproduct = compute_checkproduct( $haystack_slice );
+		$found++ if( $haystack_slice_checkproduct == $needle_checkproduct );
+	}
+	$found;
+}
+print detect_anagrams('AdnBndAndBdaBn', 'dAn');
+print "\n";
+print detect_anagrams('AbrAcadAbRa', 'cAda');
+print "\n";