Recursion: Multiplication by Addition

Create a function that returns the product of two integers. This process of multiplication can be achieved via repetitive addition, thus, the process can be done recursively.

Examples

multiply(10, 2) ➞ 20

multiply(-51, -4) ➞ 204

multiply(3, 9) ➞ 27

multiply(-21, 5) ➞ -105

multiply(1024, 7) ➞ 7168

multiply(273, -6) ➞ -1638

Notes

• You're expected to solve this challenge using a recursive approach.
• If you think recursion is fun, you can find a collection of those challenges here.