aoc2021

commit 6be072db3d40df7bc79e7d24a6ef2e7879871a2d
parent 89fb0e4d563de933d8944dad2381d544a7bcf1b1
Author: Samir Parikh <noreply@samirparikh.com>
Date:   Thu, 23 Dec 2021 18:56:23 +0000

obtain solutions for both parts 1 and 2 for Day 10 in one program

Diffstat:
A
day10.pl
 | 
94
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 94 insertions(+), 0 deletions(-)
diff --git a/day10.pl b/day10.pl
@@ -0,0 +1,94 @@
+#!/usr/bin/env perl
+
+# Day 10 Part 1
+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 %closer_for = (
+        ']' => '[',
+        '}' => '{',
+        ')' => '(',
+        '>' => '<',
+);
+my %opener_for = (
+        '[' => ']',
+        '{' => '}',
+        '(' => ')',
+        '<' => '>',
+);
+my %error_score = (
+        ']' => 57,
+        '}' => 1197,
+        ')' => 3,
+        '>' => 25137,
+);
+my %completion_score = (
+        ']' => 2,
+        '}' => 3,
+        ')' => 1,
+        '>' => 4,
+);
+my $error_score = 0;
+my @completion_scores = ();
+foreach my $line (@input) {
+    my @chunk;
+    my $state = "incomplete";
+    print $line;
+    foreach my $symbol (split //, $line) {
+        # if the symbol is an opening symbol, add it to the @chunk array
+        if ( $symbol =~ m/\[|\{|\(|\</ ) {
+            push @chunk => $symbol;
+            #print "$symbol is an opener.  ";
+            #say "current chunk is @chunk";
+        }
+        # if the symbol is a closing symbol...
+        if ( $symbol =~ m/\]|\}|\)|\>/ ) {
+            #say "$symbol is a closer";
+            # ...check if the symbol is a closing symbol for the last opened one
+            if ($closer_for{$symbol} eq $chunk[-1]) {
+                #say "$symbol is a matching closer";
+                # pop off last opening symbol from the @chunk array
+                pop @chunk;
+                #say "current chunk is @chunk";
+            # otherwise, report an error
+            } else {
+                #say "Expected $opener_for{$chunk[-1]}, but found $symbol instead.";
+                $error_score += $error_score{$symbol};
+                $state = "corrupted";
+                last; # go to next line
+            }
+        }
+    }
+    #say "\t$state";
+    if ($state eq "incomplete") {
+        my $completion_score = 0;
+        print "\t$state\t";
+        foreach (reverse @chunk) {
+            print ;
+            $completion_score = (5 * $completion_score) +
+                                $completion_score{$opener_for{$_}};
+        }
+        print "\n";
+        push @completion_scores => $completion_score;
+    } else {
+        say "\t$state";
+    }
+}
+@completion_scores = sort { $a <=> $b } @completion_scores;
+say "part 1 $error_score";
+#say "part 2 @completion_scores";
+say "part 2 ", $completion_scores[(scalar @completion_scores) / 2];