Leetcode - Multiply Strings Solution

Vishal Basumatary -

Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.

Note: You must not use any built-in BigInteger library or convert the inputs to integer directly.

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
  • num1 and num2 consist of digits only.
  • Both num1 and num2 do not contain any leading zero, except the number 0 itself.

Solution in Python

class Solution:
    def multiply(self, num1: str, num2: str) -> str:
        def to_numeric(num):
            new = 0
            for index,val in enumerate(reversed(num)):
                new += (ord(val)-48)*10**index
            return new
        return str(int(num1)*int(num2))