File Coverage

blib/lib/Math/Combinations.pm

Criterion	Covered	Total	%
statement	9	74	12.1
branch	0	10	0.0
condition	0	9	0.0
subroutine	3	8	37.5
pod	0	5	0.0
total	12	106	11.3

package Math::Combinations;

use strict;
use warnings;

use Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw(combinations_without_repetition
                 combinations_with_repetition
                 num_rem);

our $VERSION = '1.00';

sub combinations_without_repetition {
    my ($ref_words, $k) = @_;
    my $n = requirements(@_);
    $n || return;
    my $count = 0;
    my $ret_all = ();
    my ($i, @out_num);
    for $i (0..$k-1) {
        $out_num[$i] = $i;
    }
    ++$count;
    my $ret_ref = \&add_arr_comb;
    $ret_all .= ${&$ret_ref(\@out_num, $count, $ref_words)};
    while() {
        $i = $k - 1;
        while($i >= 0 && $out_num[$i] == $n - $k + $i) {
            --$i;
        }
        return $ret_all if $i < 0;
        ++$out_num[$i];
        for($i++; $i < $k; $i++) {
            $out_num[$i] = $out_num[$i - 1] + 1;
        }
        ++$count;
        $ret_all .= ${&$ret_ref(\@out_num, $count, $ref_words)};
    }
}

sub combinations_with_repetition {
    my ($ref_words, $k) = @_;
    my $n = requirements(@_);
    $n || return;
    my $count = 0;
    my $ret_all = ();
    my ($i, @out_num);
    for $i (0..$k-1) {
        $out_num[$i] = 0;
    }
    ++$count;
    my $ret_ref = \&add_arr_comb;
    $ret_all .= ${&$ret_ref(\@out_num, $count, $ref_words)};
    while() {
        $i = $k - 1;
        while($i >= 0 && $out_num[$i] == $n - 1) {
            --$i;
        }
        return $ret_all if $i < 0;
        ++$out_num[$i];
        for($i++; $i < $k; $i++) {
            $out_num[$i] = $out_num[$i - 1];
        }
        ++$count;
        $ret_all .= ${&$ret_ref(\@out_num, $count, $ref_words)};
    }
}

sub requirements {
    my ($ref_words, $k) = @_;
    if ($k <= 0 or $k > @$ref_words) {
        print "Requirements:\n";
        print "k - integer, k > 0\n";
        print "k < or = size of array\n";
        print "Quit\n";
        return;
    } else {
        scalar @$ref_words;
    }
}

sub add_arr_comb {
    my ($ref_out_num, $count, $ref_words) = @_;
    my $ret = ();
    $ret .= "($count) ";
    for my $i (0..$#$ref_out_num)  {
        $ret .= "$ref_words->[$ref_out_num->[$i]] ";
    }
    \($ret .= "\n");
}

sub num_rem {
    my $out = ();
    foreach (split(/\n/, shift)) {
        s/^\(\d+\) //;
        $out .= $_."\n";
    }
    $out;
}

1;

__END__