Method difference

src/07-set/set.ts:140–148

* Returns a new set with elements in this set but not in otherSet. * @param otherSet - The set to subtract * @returns A new set with the difference * @complexity Time O(n) | Space O(n)

(otherSet: MySet)

   * @complexity Time O(n) | Space O(n)
   */
  difference(otherSet: MySet): MySet {
    const differenceSet = new MySet();
    this.values().forEach(value => {
      if (!otherSet.has(value)) {
        differenceSet.add(value);
      }
    });
    return differenceSet;
  }

  /**
   * Returns true if every element of this set is also in otherSet.