Java/src/main/java/com/thealgorithms/maths/BinomialCoefficient.java

package com.thealgorithms.maths;

/*
 * Java program for Binomial Coefficients
 * Binomial Coefficients: A binomial coefficient C(n,k) gives number ways
 * in which k objects can be chosen from n objects.
 * Wikipedia: https://en.wikipedia.org/wiki/Binomial_coefficient
 *
 * Author: Akshay Dubey (https://github.com/itsAkshayDubey)
 *
 * */

public final class BinomialCoefficient {
    private BinomialCoefficient() {
    }

    /**
     * This method returns the number of ways in which k objects can be chosen from n objects
     *
     * @param totalObjects    Total number of objects
     * @param numberOfObjects Number of objects to be chosen from total_objects
     * @return number of ways in which no_of_objects objects can be chosen from total_objects
     *     objects
     */

    public static int binomialCoefficient(int totalObjects, int numberOfObjects) {
        // Base Case
        if (numberOfObjects > totalObjects) {
            return 0;
        }

        // Base Case
        if (numberOfObjects == 0 || numberOfObjects == totalObjects) {
            return 1;
        }

        // Recursive Call
        return (binomialCoefficient(totalObjects - 1, numberOfObjects - 1) + binomialCoefficient(totalObjects - 1, numberOfObjects));
    }
}