adventofcode/2020/05/part1.pm

35 lines
713 B
Perl

package part1;
use 5.20.0;
use warnings;
use experimental qw/
signatures
postderef
switch
/;
use parent qw/ Exporter::Tiny /;
our @EXPORT = qw/ resolve /;
sub resolve($code) {
my @row = ( 0, 127 );
my @column = ( 0, 7 );
for ( split '', $code ) {
when ('F') { $row[1] = $row[0] + int( ( $row[1] - $row[0] ) / 2 ) }
when ('B') { $row[0] = $row[0] + 1 + int( ( $row[1] - $row[0] ) / 2 ) }
when ('L') {
$column[1] = $column[0] + int( ( $column[1] - $column[0] ) / 2 )
}
when ('R') {
$column[0] = $column[0] + 1 +
int( ( $column[1] - $column[0] ) / 2 )
}
}
return 8 * $row[0] + $column[0];
}