#!/usr/bin/perl

use strict;
use warnings;

my %cache;
sub fib {
    my $n = shift;
    return $n if $n < 2;
    return ( $cache{ $n - 1 } ||= fib($n - 1) )
         + ( $cache{ $n - 2 } ||= fib($n - 2) );
}

print "Fibonnaci Fun\n\n";

print "Pick a number that represents which value of the Fibonnaci sequence you want to start with\n";
print "ie: 1 would be 1, and 2 would be 1, and 3 would be 2 and so on.\n"; 
print "Your choice: ";
chomp(my $value = <>);

print "\nNow pick a number to repesent the range you want.\n";
print "If you want to use values 1 through 10 you you need only enter 10,\n";
print "assuming of course you entered 1 above.\n";
print "Your choice: ";
chomp(my $temp = <>);

my $range = $value + $temp;

my $phiApprox;
my $fibValue1;
my $fibValue2;

for my $i ($value .. $range){
  $fibValue1 = fib($i);
  $fibValue2 = fib($i - 1);

  $phiApprox = 0 if($i <= 1);
  $phiApprox = $fibValue1 / $fibValue2 if($i >= 2);

  print "\n";
  print "$fibValue1 / $fibValue2 = $phiApprox";
}

print "\n";