#!/usr/local/bin/perl
# binomial.pl
# A script to compute the binomial coefficient C(n,k)
# 
$n=shift;
$k=shift;
$x=choose($n,$k);
$d=$n-$k;
#
print "              $n!            \n";
print "C($n,$k)=   ------- = $x     \n";
print "            $k!($d!)       \n\n";

sub choose{
    my ($n,$k)=@_;
    if(($n==0) && ($k==0)){
	return(1);
    }
    if(($n>=0) && ($k>=0) && ($n>=$k)){ 
	return(choose($n-1,$k-1)+choose($n-1,$k));
    }
}