#!/usr/bin/env/perl

use strict;
use warnings;

my @answer;   

#added to suppress warnings, but it still doesn't work.
my ($a, $b, $c) = 0;

print "0. Value of ARGV is @ARGV; Value of magic array var is @_.\n";

# Take list of arguments from any of the 4 other subroutines
 # In principle, should accept variable length arguments
 # and recursively reduce the items in list from right to left.
 #
 # Termination: @angle has 1 length. This is pushed onto @answer array.
 # Case 1: reduce negative number by adding 60 to it, and 
 #         subtracting 1 from number on left.
 # Case 2: reduce positive number >= 60 by subtracting 60 and 
 #         adding 1 to number on left.

sub reduce {
# print "0. Value of magic array var is @_.\n"; 
 my @angle = @_;
#  @_ = undef;
 my ($b, $c) = ($angle[-2], $angle[-1]); # reduce from end.

# Warnings when running test script indicate $c in the if statement is not defined.  
# But It is defined at the top, and should be defined if the @ARGV variable is being passed correctly.

  if ($c < 0 && scalar(@angle) > 1) {
   until ($c >= 0 && $c < 60) {
     $c += 60;
     $b -=  1;
     }
     unshift(@answer, $c);
     pop(@angle);
     @angle[-1] = $b;
# Debug print statements
     print "2. b = $b, c = $c\n";
     print "2. Angle array is @angle.\n ";
     print "2. Value of magic array var is @_.\n";
     print "2. Values in answer array: @answer.\n";
####
     
     &reduce(@angle);
    
  } elsif ($c >= 60 && scalar(@angle) > 1 ) {
     until ($c < 60 && $c >= 0) {
     $c -= 60;
     $b += 1;
     }
     unshift(@answer, $c);
     pop(@angle);
     @angle[-1] = $b;
# Debug print statements
     print "3. b = $b, c = $c\n";
     print "3. Angle array is @angle.\n ";
     print "3. Value of magic array var is @_.\n";
     print "3. Values in answer array: @answer.\n";
####
              
     &reduce(@angle);
    
  } elsif ( ($c >= 0 && $c < 60 ) && scalar(@angle) > 1)  {
     unshift(@answer, $c);
     pop(@angle);
     &reduce(@angle); 
  } else {
     unshift(@answer, @angle);	  	  
     print "Reduced answer: @answer \n";
 }

 return $answer;

 }


main( @ARGV ) unless caller();

sub main {
	
&reduce( @ARGV );

}