[7] Reverse Integer

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题目

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

Example 1:

Input: 123
Output: 321
Example 2:

Input: -123
Output: -321
Example 3:

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.

解法

一：

思路：

主要需要注意溢出问题

代码

LeetCode71png

改进

  • 看了解答，发现无需特意处理正负号

负数究竟是如何取模的？ - 莫里007的回答 - 知乎 https://www.zhihu.com/question/31344913/answer/51534190

  • 没有使用 long 类型

修改后的代码

LeetCode72png


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