binomial_coefficient.h

00001 
00002 /***************************************************************************
00003  *  binomial_coefficient.h - function for computing the binomial coefficient
00004  *
00005  *  Generated: Sun Nov 04 17:29:46 2007 
00006  *  Copyright  2007  Martin Liebenberg
00007  *
00008  ****************************************************************************/
00009 
00010 /*  This program is free software; you can redistribute it and/or modify
00011  *  it under the terms of the GNU General Public License as published by
00012  *  the Free Software Foundation; either version 2 of the License, or
00013  *  (at your option) any later version. A runtime exception applies to
00014  *  this software (see LICENSE.GPL_WRE file mentioned below for details).
00015  *
00016  *  This program is distributed in the hope that it will be useful,
00017  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  *  GNU Library General Public License for more details.
00020  *
00021  *  Read the full text in the LICENSE.GPL_WRE file in the doc directory.
00022  */
00023 
00024 #ifndef __UTILS_MATH_BINOMIAL_COEFFICIENT_H_
00025 #define __UTILS_MATH_BINOMIAL_COEFFICIENT_H_
00026 
00027 namespace fawkes {
00028 
00029 
00030 /** @class BinomialCoefficient <utils/math/binomial_coefficient.h>
00031  *  Contains method to compute the binomial coefficient.
00032  * 
00033  *  @author Martin Liebenberg
00034  */
00035 
00036 class BinomialCoefficient
00037 {
00038  public:
00039   /** Calculates the binomial coefficient.
00040    * @param n upper value
00041    * @param k lower value
00042    * @return the binomial coefficient of n and k
00043    */
00044   static inline unsigned int binoc(unsigned int n, unsigned int k)
00045   {
00046     unsigned int result;
00047     if(k == 0)
00048       return 1;
00049     if(2 * k > n)
00050       result = binoc(n, n - k);
00051     else
00052     {
00053       result = n;
00054       for(unsigned int i = 2; i <= k; i++)
00055       {
00056         result = result * ((n + 1 - i) / i);
00057       }
00058     }
00059     return result;
00060   }
00061 };
00062 
00063 
00064 } // end namespace fawkes
00065 
00066 #endif

Generated on Tue Feb 22 13:32:28 2011 for Fawkes API by  doxygen 1.4.7