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                             CHALLENGE 082

                                Andinus
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Table of Contents
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1. Task 1 - Common Factors
.. 1. Perl





1 Task 1 - Common Factors
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  You are given 2 positive numbers $M and $N.

  Write a script to list all common factors of the given numbers.


1.1 Perl
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  • Program: <file:perl/ch-1.pl>

  We loop over all the numbers from `1 ... $M' to get their factors &
  then just compare it with factors of `$N'. I took this code from
  Challenge 081's ch-1.pl.
  ┌────
  │ my $A = shift @ARGV;
  │ my $B = shift @ARGV;
  │
  │ # Get all common divisors.
  │ my %divisors_of_A = divisors($A);
  │ my %divisors_of_B = divisors($B);
  │ my @common_divisors;
  │ foreach my $num (sort { $a <=> $b } keys %divisors_of_A) {
  │     push @common_divisors, $num
  │         if exists $divisors_of_B{$num};
  │ }
  │
  │ # Returns all divisors of a number.
  │ sub divisors {
  │     my $n = shift @_;
  │     my %divisors;
  │     foreach my $i ( 1 ... $n){
  │         if ($n % $i == 0) {
  │             $divisors{$i} = 1;
  │         }
  │     }
  │     return %divisors;
  │ }
  │
  │ print join(', ', @common_divisors), "\n";
  └────