feat: added digital root algorithm and its recursive implementation

Maths/DigitalRoot.js

@@ -1,30 +1,30 @@
 export const digitalRoot = (num) => {
   /**
- * Calculates the digital root of a number in constant time.
- * @param {number} num - The number to compute the digital root for.
- * @returns {number} The digital root of the given number.
- *
- * @example
- * digitalRoot(456) // returns 6
- * digitalRoot(-999) // returns 9
- * digitalRoot(0) // returns 0
- */
+   * Calculates the digital root of a number in constant time.
+   * @param {number} num - The number to compute the digital root for.
+   * @returns {number} The digital root of the given number.
+   *
+   * @example
+   * digitalRoot(456) // returns 6
+   * digitalRoot(-999) // returns 9
+   * digitalRoot(0) // returns 0
+   */
   if (num < 0) num = -num;
   return num === 0 ? num : 1 + ((num - 1) % 9);
 };
 /*------------------------------------------------------------------------------------*/
 
 export const digitalRootRecursive = (num) => {
   /**
- * Calculates the digital root of a number using recursion.
- * @param {number} num - The number to compute the digital root for.
- * @returns {number} The digital root of the given number.
- *
- * @example
- * digitalRoot(456) // returns 6
- * digitalRoot(999) // returns 9
- * digitalRoot(0) // returns 0
- */
+   * Calculates the digital root of a number using recursion.
+   * @param {number} num - The number to compute the digital root for.
+   * @returns {number} The digital root of the given number.
+   *
+   * @example
+   * digitalRoot(456) // returns 6
+   * digitalRoot(999) // returns 9
+   * digitalRoot(0) // returns 0
+   */
   if (num < 0) num = -num; // Handle negative input by converting to positive
   if (num < 10) return num; // Base case for single-digit number