aoc2021

commit 7ce68a84a25ccd87fa83d215b351da6a671dccda
parent 5ace50df951bb672c4388992a442a7a66da24630
Author: Samir Parikh <noreply@samirparikh.com>
Date:   Thu, 23 Dec 2021 02:17:43 +0000

initial commit for day10-1.pl

Diffstat:
A
day10-1.pl
 | 
56
++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 56 insertions(+), 0 deletions(-)
diff --git a/day10-1.pl b/day10-1.pl
@@ -0,0 +1,56 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use v5.22;
+use Data::Dumper;
+
+sub get_filehandle {
+  if (@ARGV !=1) {
+    die "Usage: $0 [input-filename]";
+  }
+  my $input_filename = $ARGV[0];
+  open my $filehandle, '<', $input_filename or
+    die "Could not open input file $input_filename: $!";
+  return $filehandle;
+}
+
+my $filehandle  =  get_filehandle();
+chomp( my @input = ( <$filehandle> ) );
+my @symbols  = qw( braces brackets parentheses comparison );
+my %symbol_count;
+my %count_map = (
+        '[' => ['braces',       1],
+        ']' => ['braces',      -1],
+        '{' => ['brackets',     1],
+        '}' => ['brackets',    -1],
+        '(' => ['parentheses',  1],
+        ')' => ['parentheses', -1],
+        '<' => ['comparison',   1],
+        '>' => ['comparison',  -1],
+);
+foreach my $line (@input) {
+    %symbol_count = map { $_ => 0 } @symbols; # reset count for each line
+    my $inner_most; # inner most opening character
+    say $line;
+
+# $symbol is each character (e.g. '[', '}', '(', '>') in the line.
+# The value of $count_map{$symbol} is a reference to a two-element array.
+# The first element of the array ([0]) is the name of matching open/close
+# character (e.g. "braces", "brackets", etc.)  The second element of that
+# array ([1]) is an integer which indicates whether it is an opening
+# character (1) or closing character (-1).  We can reference these array
+# values by dereferencing:
+#       $count_map{$symbol}->[0] or $count_map{$symbol}->[1]
+# These values are used to update the count of each symbol stored in
+# %symbol_count.
+
+    foreach my $symbol (split //, $line) {
+        say "$symbol $count_map{$symbol}->[0]\t$count_map{$symbol}->[1]";
+        $symbol_count{$count_map{$symbol}->[0]} += $count_map{$symbol}->[1];
+# if the symbol is an opening character, note that in $inner_most
+        $inner_most = $count_map{$symbol}->[0] if ($count_map{$symbol}->[0] == 1);
+        #print Dumper (\%symbol_count);
+    }
+    print Dumper (\%symbol_count);
+}