64 lines
No EOL
1.5 KiB
Perl
64 lines
No EOL
1.5 KiB
Perl
package BinaryGap;
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use Modern::Perl;
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# use List::MoreUtils qw(first_index); # codility does not have
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use List::Util qw(max first);
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use Data::Dumper;
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sub solution {
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# N is an integer within the range [1..2,147,483,647]
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my ($N) = @_;
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my $max_gap = 0;
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# Make sure number is in acceptable range, if not return 0
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if (($N < 1) || ($N > '2147483647')) {
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return $max_gap;
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}
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# convert integer to binary
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my $bin_num = unpack("B*", pack("N", $N));
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# convert to array
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my @bin_array = split('',$bin_num);
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# find first 1. If there is not one, return for performance
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my $first_index;
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for (0 .. $#bin_array) {
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if ($bin_array[$_] == 1) {
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$first_index = $_;
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last;
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}
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}
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return $max_gap unless $first_index;
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# If there are less than two 1s in the array, return 0
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my $ones_total_count = grep { $_ == 1 } @bin_array;
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if ($ones_total_count < 2) {
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return $max_gap;
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}
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# If there is just one 0 in the array, return 0
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my $zeros_total_count = grep { $_ == 0 } @bin_array;
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if ($zeros_total_count < 2) {
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return $max_gap;
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}
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# Get all 1 indexes
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my @i = grep { $bin_array[$_] == 1 } 0 .. $#bin_array;
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my $last_index = $i[$#i];
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my $zero_count = 0;
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for my $index ($first_index .. $last_index) {
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my $num = $bin_array[$index];
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if ($num == 1) {
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$zero_count = 0;
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}
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else {
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$zero_count++;
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$max_gap = max($zero_count, $max_gap);
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}
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}
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return $max_gap;
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}
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1; |