2022/17.pl

   1 #!/usr/bin/perl -w
   2
   3 use v5.36;
   4 use strict;
   5 use experimental 'multidimensional';
   6
   7 my %seen = ("0,0" => 1);
   8 my ($x, $y, $tx, $ty) = (0, 0, 0, 0);
   9
  10 while (<>) {
  11         my ($dir, $len) = /^(.) (\d+)/;
  12
  13         while ($len--) {
  14                 if ($dir eq 'U') {
  15                         $y--;
  16                 } elsif ($dir eq 'D') {
  17                         $y++;
  18                 } elsif ($dir eq 'L') {
  19                         $x--;
  20                 } elsif ($dir eq 'R') {
  21                         $x++;
  22                 }
  23
  24                 if ($x == $tx) {
  25                         if ($y == $ty - 2) {
  26                                 $ty--;
  27                         } elsif ($y == $ty + 2) {
  28                                 $ty++;
  29                         }
  30                 } elsif ($y == $ty) {
  31                         if ($x == $tx - 2) {
  32                                 $tx--;
  33                         } elsif ($x == $tx + 2) {
  34                                 $tx++;
  35                         }
  36                 } elsif ($x == $tx - 2) {
  37                         $tx--;
  38                         if ($y > $ty) {
  39                                 $ty++;
  40                         } else {
  41                                 $ty--
  42                         }
  43                 } elsif ($x == $tx + 2) {
  44                         $tx++;
  45                         if ($y > $ty) {
  46                                 $ty++;
  47                         } else {
  48                                 $ty--;
  49                         }
  50                 } elsif ($y == $ty - 2) {
  51                         $ty--;
  52                         if ($x > $tx) {
  53                                 $tx++;
  54                         } else {
  55                                 $tx--;
  56                         }
  57                 } elsif ($y == $ty + 2) {
  58                         $ty++;
  59                         if ($x > $tx) {
  60                                 $tx++;
  61                         } else {
  62                                 $tx--;
  63                         }
  64                 }
  65                 $seen{"$tx,$ty"}++;
  66                 say "$x,$y $tx,$ty";
  67         }
  68 }
  69
  70 say scalar keys %seen;
  71