FibonacciNumber

Maths/FactorialRecursion.java

@@ -0,0 +1,26 @@
+package Maths;
+
+public class FactorialRecursion {
+
+    /* Driver Code */
+    public static void main(String[] args) {
+        assert factorial(0) == 1;
+        assert factorial(1) == 1;
+        assert factorial(2) == 2;
+        assert factorial(3) == 6;
+        assert factorial(5) == 120;
+    }
+
+    /**
+     * Recursive FactorialRecursion Method
+     *
+     * @param n The number to factorial
+     * @return The factorial of the number
+     */
+    public static long factorial(int n) {
+        if (n < 0) {
+            throw new IllegalArgumentException("number is negative");
+        }
+        return n == 0 || n == 1 ? 1 : n * factorial(n - 1);
+    }
+}