Add binomial coefficients (TheAlgorithms#2835)

itsAkshayDubey · web-flow · commit 1869eab0423b · 2021-11-22T15:22:15.000+02:00
diff --git a/src/main/java/com/thealgorithms/maths/BinomialCoefficient.java b/src/main/java/com/thealgorithms/maths/BinomialCoefficient.java
@@ -0,0 +1,46 @@
+package com.thealgorithms.maths;
+
+/*
+ * Java program for Binomial Cofficients
+ * Binomial Cofficients: A binomial cofficient 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 class BinomialCoefficient {
+	
+	/**
+     * This method returns the number of ways in which k objects can be chosen from n objects
+     *
+     * @param total_objects Total number of objects
+     * @param no_of_objects 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
+     */
+	
+	static int binomialCoefficient(int total_objects, int no_of_objects) {
+		
+		//Base Case
+		if(no_of_objects > total_objects) {
+			return 0;
+		}
+		
+		//Base Case
+		if(no_of_objects == 0 || no_of_objects == total_objects) {
+			return 1;
+		}
+		
+		//Recursive Call
+		return binomialCoefficient(total_objects - 1, no_of_objects - 1)
+				+ binomialCoefficient(total_objects - 1, no_of_objects);
+	}
+	
+	public static void main(String[] args) {
+		System.out.println(binomialCoefficient(20,2));
+		
+		//Output: 190
+	}
+
+}
