first few days

2/2.pl

@@ -0,0 +1,40 @@
+#!/usr/bin/perl
+
+use strict;
+
+chomp (my @data = <STDIN>);
+
+foreach my $w (@data) {
+	print checksum($w, @data);
+}
+
+
+
+sub checksum ($@) {
+	my $word = shift;
+	my @list = @_;
+
+	my @word = split //, $word;
+	
+	foreach my $w (@list) {
+		
+		my @w = split //, $w;
+		# word lengths are all equal.
+
+		my $diff = 0;
+		my $common;
+		for (my $i = 0; $i <= $#word; $i++) {
+			if ($word[$i] ne $w[$i]) {
+				$diff++
+			} else {
+				$common .= $w[$i];
+			}
+		}
+		if ($diff == 1) {
+			print "$word, $w, $diff, $common\n";
+			exit;
+		}
+
+	}
+
+}