Add Strings
Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2. Note The length of both num1 and num2 is < 5100. Both num1 and num2 contains only digits 0-9. Both num1 and num2 does not contain any leading zero. You must not use any built-in BigInteger library or convert the inputs to integer directly. Solution class Solution: def addStrings(self, num1: str, num2: str) -> str: if len(num1) < len(num2): return self.