golf - n choose p

choose.pl

# current solution:
<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$r/$c*$_-$_}print
######################################################
=pod
All of my scratch getting to this point:

<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$_*$r/$c-$_}print

while

$_=<>;$c=1;s/(\d+)/$1?$c*=$1-1:''/e while/\d/;print$c;


 join'*',1..$1,1..$2,1..$2-$1

s!(\d+), (\d+)!(join'*',$1-$2+1..$1).'/'.join'*',1..$2!e

y!0-9!/!c
s!,!/!;

#!perl -p s/(\d+), (\d+)/join'*',$..$1/e;eval;
s/(\d+), (\d+)/join'*',1..$1,'/(',1..$2,')',1..$1-$2,')'/ 
s/(\d+)/join'*',$..$1/e;y/(\d+)/$1/s;



<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$r/$c*$_-$_}print

<>=~/,/;$r=++$_+$`;while($c++-$'){$_*=($r/$c-1)}print


<>=~/,/;$r=$`+1;$_=1;while($c++-$'){$_=$_*$r/$c-$_}print

<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$r/$c*$_-$_}print

<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$_*($r/$c)-$_}print
<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$_*($r/$c)-$_}print

<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$_*$r/$c-$_}print
<>=~/,/;$r=++$_+$`;while($c++-$'){$_=$_*($r/$c)-$_}print


<>=~/,/;@a=map{eval join'*',1..0+$_||1}($`,$',$`-$');print $a[0]/($a[1]*$a[2])
<>=~/,/;sub c{eval join'*',1..0+pop||1}print c($`)/(c($')*c$`-$')

#!perl -F, -ap $r=$F[0]+1;$_=1;while($c++!=$F[1]){$_=$_*$r/$c-$_}
#!perl -F, -ap ($r,$c)=@F;while($c--){$_=$_*$r/$c-$_}

<>=~/,/;$r=$`+1;sub c{$_=pop;$c++==$'?print:c($_*$r/$c-$_)}c$.

<>=~/,/;$r=$`+1;$_=1;sub c{$c++==$'?print:$_=$_*$r/$c-$_;c}c

<>=~/,/;$r=$`+1;$_=1;while($c++!=$'){$_*=($r/$c-1)}print
<>=~/,/;$r=$`+1;$_=1;while($c++!=$'){$_*=($r/$c-1)}print


#!perl -p /,/;$r=$`+1;$_*=$r/$c-$_ if$c++==$';

<>=~/,/;sub c{eval join'*',1..0+pop||1}print c($`)/(c($')*c$`-$')

<>=~/,/;$r=$`+1;sub c{$_=pop;$c++==$'?print:c($_*$r/$c-$_)}c$.
<>=~/,/;sub c{($_,$r,$c)=@_;$c++==$'?print:c($_*$r/$c-$_,$r,$c)}c(1,$`+1,0)
<>=~/,/;$r=$`+1;sub c{($_,$c)=@_;$c++==$'?print:c($_*$r/$c-$_,$c)}c(1,0)


<>=~/,/;sub c{($v,$r,$c)=@_;$c++==$'?print$v:c($v*($r/$c-1),$r,$c)}c(1,$`+1,0)

<>=~/,/;sub c{($v,$r,$c)=@_;$c++==$'?print$v:c($v*$r/$c-$v,$r,$c)}c(1,$`+1,0)


#!perl -p /,/;}{


<>=~/, (\d+)/;sub c{$_[0]?$_[0]*c($_[0]-1):1}print c($`)/(c($1)*c($`-$1))

<>=~/,/;do{(my$t=$_)=~s/(\d)/join'*',1..$1||1/eg};
<>=~/,/;s/(\d)/join'*',1..$1||1/eg;print eval

<>=~/,/;print map{join'*',1..0+$_||1}($`,$',$`-$')

<>=~/,/;$_="$`/($'*".($`-$').")";s/(\d)/join'*',1..$1||1/eg;print eval
<>=~/,/;$a=$`-$';print eval "$`/($'*$a)"=~s/(\d)/join'*',1..$1||1/egr

<>=~/,/;$c="$`/($'*($`-$'))";$t=~s/(\d)/join'*',1..$1||1/g;print eval$t;

<>=~/(\d+)..(\d+)/;sub c{$a*=$_ for(1..$_[0])}print c($1)/(c($2)*c($1-$2))


<>=~/, (\d+)/;sub c{eval join'*',(1..pop)}print c($`)/(c($1)*c($`-$1))

<>=~/,/;sub c{eval join'*',1..0+pop||1}print c($`)/(c($')*c($`-$'))



<>=~/,/;sub c{eval join'*',pop..0+pop||1}print(1/c$',1)*c$`,$`-$'+1


<>=~/,/;print map{join'*',1..0+$_||1}($`,$',$`-$')


<>=~/,/;sub c{join'*',1..0+pop||1}eval"print c($`)/(c($')*c($`-$'))"



<>=~/, (\d+)/;sub c{$_[0]?$_[0]*c$_[0]-1:1}print c($`)/(c($1)*c($`-$1))
c($`)/(c($1)*c($`-$1))
c($`,$1)/c($`-$1,1)
sub c{$_[0]?$_[0]*c($_[0]-1):1}
sub c{($a,$b)=@_;$a==$b?$a:c($a-1,$b)}

sub c{$_[0]?$_[0]*c($_[0]-1):1}print c($`)/(c($1)*c($`-$1))
<>=~/, (\d+)/;$1=~s/(\d+)/$1-1*/ eval



# 83
#perl -F, -ape
#sub c{$_[0]?$_[0]*c($_[0]-1):1}($n,$k)=@F;$_=c($n)/(c($k)*c($n-$k))

#sub c{$_[0]?$_[0]*c($_[0]-1):1}$_=c($F[0])/(c($F[1])*c($F[0]-$F[1]))

#sub c{$_[0]?$_[0]*c($_[0]-1):1}$_=c($1)/(c($2)*c($1-$2))

# 78
#<>=~/(\d+)..(\d+)/;sub c{$_[0]?$_[0]*c($_[0]-1):1}print c($1)/(c($2)*c($1-$2))

=cut

Still working on getting this shorter. I'm sure that a pure regex solution is the way to go, I really need to avoid the loss of precision that this solution introduces.