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Re (tilly) 1: (Golf as well): List of Partitions

by tilly (Archbishop)
on May 06, 2001 at 16:32 UTC ( #78344=note: print w/replies, xml ) Need Help??

in reply to (Golf as well): List of Partitions

Occasionally I wish I hadn't given away most of my math books, this is one of those occasions. I had a book with lots about partitions in it, but I long ago gave it away. However this problem is quite doable. The trick is to make P a function of 2 variables, first the number n you are interested in partitioning, and then the number i that is the largest number you are willing to partition it into.

With that tip, here is an answer in 90 characters:

sub P { my($n,$i)=@_;$i||=$n;$i-1?map{my$c=$_;map[($i)x$c,@$_],P($n-$c*$i,$i-1 +)}0..$n/$i:[(1) x$n] }