---
tags: data_structure_python
---

# Reverse Integer <img src="https://img.shields.io/badge/-easy-brightgreen">

Given a 32-bit signed integer, reverse digits of an integer.

<ins>**Example 1:**</ins>

>Input: 123
>Output: 321

<ins>**Example 2:**</ins>

>Input: -123
>Output: -321

<ins>**Example 3:**</ins>

>Input: 120
>Output: 21

**Note:**

Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: $[−231, 231 − 1]$. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

## Solution

class Solution:
    def reverse(self, x: int) -> int:
        res = 0
    
        if x < 0:
            sign = -1
            x = -x
        else:
            sign = 1

        while x != 0:
            res = 10 * res + (x % 10)
            
            if  res < -2**31 or res > 2**31 - 1:
                return 0
            
            x = x // 10
            
        return sign * res