Computes (N choose K), the number of ways to select K different elements from a set of size N. - Java java.lang

Java examples for java.lang:Math Calculation

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Description

Computes (N choose K), the number of ways to select K different elements from a set of size N.

Demo Code

// Copyright (C) 2002-2012 Three Rings Design, Inc., All Rights Reserved
//package com.java2s;

public class Main {
    /**//from   ww  w  . j  ava2  s  . c o m
     * Computes (N choose K), the number of ways to select K different elements from a set of size
     * N.
     */
    public static int choose(int n, int k) {
        // Base case: One way to select or not select the whole set
        if (k <= 0 || k >= n) {
            return 1;
        }

        // Recurse using pascal's triangle
        return (choose(n - 1, k - 1) + choose(n - 1, k));
    }
}

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