number generator
Marc 'BlackJack' Rintsch
bj_666 at gmx.net
Sat Mar 10 10:16:15 CET 2007
In <1173515984.515050.27400 at n33g2000cwc.googlegroups.com>, Raymond
Hettinger wrote:
> On Mar 9, 7:32 am, Marc 'BlackJack' Rintsch <bj_... at gmx.net> wrote:
>> In <1173453432.893222.308... at j27g2000cwj.googlegroups.com>, cesco wrote:
>> > Given two positive integers, N and M with N < M, I have to generate N
>> > positive integers such that sum(N)=M. No more constraints.
>>
>> Break it into subproblems. Generate a random number X from a suitable
>> range and you are left with one number, and the problem to generate (N-1)
>> random numbers that add up to (M-X).
>
> This approach skews the probabilities. The OP said for example with
> N=5 and M=50 that a possible solution is [3, 11, 7, 22, 7]. You're
> approach biases the probabilities toward solutions that have a large
> entry in the first position.
I know but he said also "No more constraints". And…
> To make the solutions equi-probable, a simple approach is to
> recursively enumerate all possibilities and then choose one of them
> with random.choice().
…it would be faster than creating all possibilities. :-)
Ciao,
Marc 'BlackJack' Rintsch
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