Author serhiy.storchaka
Recipients lemburg, mark.dickinson, serhiy.storchaka, stutzbach
Date 2019-06-01.20:47:29
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Message-id <1559422049.94.0.857716315829.issue37128@roundup.psfhosted.org>
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Content
The function which returns the number of ways to choose k items from n items without repetition and without order was added in issue35431. This functions is always goes in pair with other function, which returns the number of ways to choose k items from n items without repetition and with order. These functions are always learned together in curses of combinatorics. Often C(n,k) is determined via P(n,k) (and both are determined via factorial).

    P(n, k) = n! / (n-k)!
    C(n, k) = P(n, k) / k!

The proposed PR adds meth.perm(). It shares most of the code with math.comb().
History
Date User Action Args
2019-06-01 20:47:30serhiy.storchakasetrecipients: + serhiy.storchaka, lemburg, mark.dickinson, stutzbach
2019-06-01 20:47:29serhiy.storchakasetmessageid: <1559422049.94.0.857716315829.issue37128@roundup.psfhosted.org>
2019-06-01 20:47:29serhiy.storchakalinkissue37128 messages
2019-06-01 20:47:29serhiy.storchakacreate