NAME comb - combinatorial number SYNOPSIS comb(x, y) TYPES x integer y integer return integer DESCRIPTION Return the combinatorial number C(x,y) which is defined as: x! --------- y!*(x-y)! This function computes the number of combinations in which y things may be chosen from x items ignoring the order in which they are chosen. EXAMPLE ; print comb(7,3), comb(7,4), comb(7,5), comb(3,0), comb(0,0) 35 35 21 1 1 ; print comb(2^31+1,2^31-1) 2305843010287435776 LIMITS x >= y >= 0 y < 2^24 x-y < 2^24 LINK LIBRARY void zcomb(ZVALUE x, ZVALUE y, ZVALUE *res) SEE ALSO fact, perm, randperm ## Copyright (C) 1999-2006 Landon Curt Noll ## ## Calc is open software; you can redistribute it and/or modify it under ## the terms of the version 2.1 of the GNU Lesser General Public License ## as published by the Free Software Foundation. ## ## Calc is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY ## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General ## Public License for more details. ## ## A copy of version 2.1 of the GNU Lesser General Public License is ## distributed with calc under the filename COPYING-LGPL. You should have ## received a copy with calc; if not, write to Free Software Foundation, Inc. ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ## ## Under source code control: 1994/10/20 04:03:02 ## File existed as early as: 1994 ## ## chongo /\oo/\ http://www.isthe.com/chongo/ ## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/