-
Notifications
You must be signed in to change notification settings - Fork 0
/
day21b.pl
97 lines (77 loc) · 1.89 KB
/
day21b.pl
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
#!/usr/bin/env perl
use feature ':5.16';
use strict;
use warnings;
use utf8;
use Path::Tiny;
{ package Game;
sub rolls {
my ($self) = @_;
return $self->{ rolls } if ($self->{ rolls });
$self->{ rolls } = {};
for my $one (1 .. 3) {
for my $two (1 .. 3) {
for my $thr (1 .. 3) {
my $roll = $one + $two + $thr;
$self->{ rolls }{ $roll }++;
}
}
}
return $self->{ rolls };
}
sub roll {
my ($self, $player) = @_;
my %rolls = %{ $self->rolls() };
my $games = {};
my $winner = 21;
for my $scen (keys %{ $self->{ games } }) {
my $num = $self->{ games }{ $scen };
my ($pos1, $score1, $pos2, $score2) = split( ',', $scen );
for my $roll (keys %rolls) {
my $count = $rolls{ $roll };
my ($pos, $score, $next);
if ($player) {
$pos = ($pos2 + $roll) % 10;
$score = $score2 + $pos + 1;
$next = "$pos1,$score1,$pos,$score"
}
else {
$pos = ($pos1 + $roll) % 10;
$score = $score1 + $pos + 1;
$next = "$pos,$score,$pos2,$score2";
}
if ($score >= $winner) {
$self->{ wins }[$player] += $num * $count;
}
else {
$games->{ $next } += $num * $count;
}
}
}
$self->{ games } = $games;
return %{ $self->{ games } } == 0;
}
sub new {
my ($class, $p1, $p2) = @_;
$p1--;
$p2--;
my $self = {
games => { "$p1,0,$p2,0" => 1 },
wins => [0, 0],
count => 0,
};
bless $self, $class;
return $self;
}
}
my $input_file = $ARGV[0] || 'input21.txt';
my $input = Path::Tiny::path( $input_file )->slurp_utf8( { chomp => 1 } );
my ($p1, $p2) = ($input =~ /position: (\d+)$/smg);
my $game = Game->new( $p1, $p2 );
while (1) {
last if ($game->roll(0));
last if ($game->roll(1));
}
print "Player 1 wins in $game->{ wins }[0] universes\n";
print "Player 2 wins in $game->{ wins }[1] universes\n";
exit;