http://qs1969.pair.com?node_id=631016


in reply to Re^2: One Zero variants_without_repetition
in thread One Zero variants_without_repetition

Okay, sorry! Try this iterator then. It will handle upto 32 0s + 1s.

If you uncomment the second example it runs on a bit.

Update: Had to tweak the termination condition. It works now but I'm not happy with it.

Update2: D'oh! No need to count both 1s and 0s.

#! perl -slw use strict; sub combs { my( $ones, $zeros ) = @_; my $n = $ones+$zeros; my $max = 2**$n; my $p = 0; return sub { my $x = ''; $x = unpack "b$n", pack 'V', $p++ until $x =~ tr[1][] == $ones or $p > $max and return; return $x; } } my $iter = combs( 2, 3 ); print while $_ = $iter->(); #my $iter = combs( 14, 6 ); #print while $_ = $iter->(); __END__ C:\test>junk7 11000 10100 01100 10010 01010 00110 10001 01001 00101 00011

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