Asp Forum - Re: Beginner question

William James

3/11/2016 11:29:00 PM

Pascal Bourguignon wrote:

> But you're not doing the same thing. Better use do than loop:
>
>
> (defun put-stones-to-strip-i (strip stones)
> (do ((current strip (or (cdr current) strip))
> (remains stones (1- remains)))
> ((< remains 0) strip)
> (incf (car current))))
>
>
>
> On the other hand, stones is often enough much greater than (length
> strip), it would be more efficient to do:
>
>
> (defun put-stones-to-strip-a (strip stones)
> (multiple-value-bind (stone/slot remainder) (truncate stones (length strip))
> (do ((current strip (cdr current)))
> ((null current) strip)
> (if (< 0 remainder)
> (progn (decf remainder)
> (incf (car current) (1+ stone/slot)))
> (incf (car current) stone/slot)))))

OCaml:

let put_stones_to_vector strip stones =
for i = 0 to stones - 1 do
let j = i mod (Array.length strip) in
strip.(j) <- strip.(j) + 1
done ;;

# let strip = [|0;0;0;0;0;0;0;0|];;
val strip : int array = [|0; 0; 0; 0; 0; 0; 0; 0|]
# put_stones_to_vector strip 3;;
- : unit = ()
# strip;;
- : int array = [|1; 1; 1; 0; 0; 0; 0; 0|]
# put_stones_to_vector strip 22;;
- : unit = ()
# strip;;
- : int array = [|4; 4; 4; 3; 3; 3; 2; 2|]
# Array.fold_left (+) 0 strip;;
- : int = 25

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comp.lang.lisp

Re: Beginner question

William James

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