Multiply Strings

Medium

Given two non-negative integers num1 and num2 represented as strings, return the product, also as a string. Do not use any built-in big-integer library or convert the inputs directly to an integer.

Example 1

Input:  num1 = "2", num2 = "3"
Output: "6"

Example 2

Input:  num1 = "123", num2 = "456"
Output: "56088"

Constraints

• 1 <= num1.length, num2.length <= 200
• The numbers contain only digits and have no leading zero (except "0").