Challenge 004 task 2

1 files changed, 40 insertions, 0 deletions

diff --git a/challenge-004/jo-37/perl/ch-2.pl b/challenge-004/jo-37/perl/ch-2.pl
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+++ b/challenge-004/jo-37/perl/ch-2.pl
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+#!/usr/bin/perl -s
+
+use v5.16;
+use warnings;
+use experimental 'signatures';
+
+our $letters;
+
+die <<EOS unless @ARGV && $letters;
+usage: $0 -letters=LETTERS [FILE]
+
+-letters=LETTERS
+    list of letters
+
+FILE
+    Name of a file containing one word per line. Use '-' for STDIN.
+
+EOS
+
+
+### Input and Output
+
+main: {
+    my %letters;
+    $letters{$_}++ for split //, lc $letters;
+    while (<>) {
+        chomp;
+        say if check_word(\%letters, lc);
+    }
+}
+
+### Implementation
+
+sub check_word ($letters, $word) {
+    my %letters = %$letters;
+    for my $l (split //, $word) {
+        return unless exists $letters{$l} && $letters{$l}--;
+    }
+    1;
+}