[Newbies] Re: Another extension proposal -> subsets

[nicolas cellier]

cdrick <cdrick65 <at> gmail.com> writes:

> 
> Yes.. Nico's solution is lot faster...
> 
> set := #(1 2 3 4 5) asSet.
> [ set subsets  "mine"] timeToRun ." 1"
> [ set subsets2  "Zulk first"  ] timeToRun. " 8"
> [ set subsets4  "Nicolas"] timeToRun. " 1"
> [ set subsets5  "Zulk"] timeToRun. " 2"
> 
> set := (1 to: 10) asSet.
> [ set subsets  ] timeToRun . " 46"
> [ set subsets4  ] timeToRun. " 18"
> [ set subsets5  ] timeToRun." 114"
> 
> set := (1 to: 15) asSet.
> [ set subsets  ] timeToRun ." 2484"
> [ set subsets4  ] timeToRun. " 1598"
> [ set subsets5  ] timeToRun." 12493"
> 
> Nicolas won ;) So maybe we can add this one and rename the
> combinations:atATime: ?
> 
> Cédrick
> 

He, press ALT-v to get versions of #combinations:atATimeDo: and thanks tk!

I like bit sift solution too for it's simplicity.
The problem is that it will iterate p times for creating each subset of size p.
#combinations:atATimeDo: does not. It is building subsets in parallel.
The required copy does an iteration though, but in a primitive!
Hence the difference...

Nicolas