Tim Peters <t...@python.org> added the comment:
[Tim] > That's [Mark's code] cheaper than almost every case handled by > perm_comb_small()'s current ... "iscomb" loop. Although I should clarify they're aimed at different things, and don't overlap all that much. Mark's code, & even more so Raymond's extension, picks on small "n" and then looks for the largest "k" such that comb(n, k) can be done with supernatural speed. But the existing perm_comb_small() picks on small "k" and then looks for the largest "n" such that "the traditional" one-at-a-time loop can complete without ever overflowing a C uint64 along the way. The latter is doubtless more valuable for perm_comb_small(), since its recursive calls cut k roughly in half, and the first such call doesn't reduce n at all. But where they do overlap (e.g., comb(50, 15)), Mark's approach is much faster, so that should be checked first. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue37295> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
