## Statement

• Difficulty: Easy
• Tag: `数学` `字符串` `模拟`

``````输入：num1 = "11", num2 = "123"

``````

``````输入：num1 = "456", num2 = "77"

``````

``````输入：num1 = "0", num2 = "0"

``````

• `1 <= num1.length, num2.length <= 104`
• `num1``num2` 都只包含数字 `0-9`
• `num1``num2` 都不包含任何前导零

• Difficulty: Easy
• Tag: `Math` `String` `Simulation`

Given two non-negative integers, `num1` and `num2` represented as string, return the sum of `num1` and `num2` as a string.

You must solve the problem without using any built-in library for handling large integers (such as `BigInteger`). You must also not convert the inputs to integers directly.

Example 1:

``````Input: num1 = "11", num2 = "123"
Output: "134"
``````

Example 2:

``````Input: num1 = "456", num2 = "77"
Output: "533"
``````

Example 3:

``````Input: num1 = "0", num2 = "0"
Output: "0"
``````

Constraints:

• `1 <= num1.length, num2.length <= 104`
• `num1` and `num2` consist of only digits.
• `num1` and `num2` don't have any leading zeros except for the zero itself.

## Solution

``````class Solution:
def addStrings(self, num1: str, num2: str) -> str:
return str(int(num1) + int(num2))
``````