#!/usr/bin/perl -w
use strict;
use Math::Big qw/factorial/;

# Variation (Mit Beachtung der Reihenfolge) / Permutation (When order matters)
# Kombination (Ohne Beachtung der Reihenfolge) / Combination (When the order does not matter)

# n = # of total
# k = # of used

# Variation mit Zurücklegen / Permutation with repetition
# n ** k;

# Variation ohne Zurücklegen / Permutation without repetition
# n!
# --------
# (n - k)!

# Kombination mit Zurücklegen / Combination with repetition
# (n + k - 1)!
# -------------
# k! * (n - 1)!

# Kombination ohne Zurücklegen / Combination without repetition
# n!
# -------------
# k! * (n - k)!

my $n = 26;
my $k = 130000;

print 'USED: ' . $k . ' OF TOTAL: ' . $n . "\n";

my $p_w_r = $n ** $k;
print 'PERMUTATION WITH REPETITION: ' . $p_w_r . ' (e.g. ZAHLENSCHLOSS)' . "\n";

my $p_wo_r = factorial($n) / factorial($n - $k);
print 'PERMUTATION WITHOUT REPETITION: ' . $p_wo_r . ' (e.g. REIHENFOLGE VON BILDERN AN DER WAND)' . "\n";

my $c_w_r = factorial($n + $k - 1) / (factorial($k) * factorial($n - 1));
print 'COMBINATION WITH REPETITION: ' . $c_w_r . ' (e.g. GUMMIBAEREN ORACLE)' . "\n";

my $c_wo_r = factorial($n) / (factorial($k)* factorial($n-$k));
print 'COMBINATION WITHOUT REPETITION: ' . $c_wo_r . ' (e.g. LOTTO, POKER)' . "\n";