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A Java API for Meta-CSP based reasoning
/*******************************************************************************
* Copyright (c) 2010-2013 Federico Pecora
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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package org.metacsp.utility;
/**
* Computes binomial(N, K) using Pascal's identity (binomial(n, k) = binomial(n-1, k-1) + binomial(n-1, k))
* and dynamic programming.
* @author Robert Sedgewick and Kevin Wayne (Princeton University, Dept. of Computer Science)
*
*/
public class Binomial {
public static long binomial(int N, int K) {
long[][] binomial = new long[N+1][K+1];
// base cases
for (int k = 1; k <= K; k++) binomial[0][k] = 0;
for (int n = 0; n <= N; n++) binomial[n][0] = 1;
// bottom-up dynamic programming
for (int n = 1; n <= N; n++)
for (int k = 1; k <= K; k++)
binomial[n][k] = binomial[n-1][k-1] + binomial[n-1][k];
return binomial[N][K];
}
}