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
|
#!/usr/bin/env perl
use strict;
use warnings;
use List::Util 'min';
# use Smart::Comments;
use Data::Dumper;
sub manhattan_distance {
my $ref = shift;
my ($x, $y) = @{$ref};
return abs(0 - $x) + abs(0 - $y);
}
sub pedometer {
my $ref = shift;
my ($x, $y, $step_1, $step_2) = @{$ref};
return $step_1 + $step_2;
}
my %directions = (
'U' => [0, 1],
'D' => [0,-1],
'R' => [1, 0],
'L' => [-1,0]
);
my $turn = 0;
my @intersections = ();
my %map;
while(<>) {
chomp;
my @path = split /,/;
my @coord = (0,0); # Starting point
my $num_steps = 0;
if (!$turn){
foreach my $way (@path) {
my ($dir, $speed) = ($1, $2) if ($way =~ /(\w)(\d+)/) or die "$!";
for (1..$speed) {
$coord[0] += @{$directions{$dir}}[0];
$coord[1] += @{$directions{$dir}}[1];
$num_steps++;
$map{"$coord[0],$coord[1]"} = $num_steps;
}
}
$turn = !$turn;
} else {
foreach my $way (@path) {
my ($dir, $speed) = ($1, $2) if ($way =~ /(\w)(\d+)/) or die "$!";
for (1..$speed) {
$coord[0] += @{$directions{$dir}}[0];
$coord[1] += @{$directions{$dir}}[1];
$num_steps++;
if (exists $map{"$coord[0],$coord[1]"}) {
push @intersections, [@coord,$num_steps,$map{"$coord[0],$coord[1]"}];
}
}
}
}
}
# print Dumper \@intersections;
print(min(map {pedometer($_);} @intersections));
|
