2019-05-02 15:59:01 +08:00
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# LeetCode 第 344 号问题:反转字符串
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> 本文首发于公众号「五分钟学算法」,是[图解 LeetCode ](<https://github.com/MisterBooo/LeetCodeAnimation>)系列文章之一。
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>
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> 个人网站:[https://www.cxyxiaowu.com](https://www.cxyxiaowu.com)
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题目来源于 LeetCode 第 344 号问题:反转字符串。面试官最喜欢让你手写的一道算法题!
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### 题目描述
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编写一个函数,其作用是将输入的字符串反转过来。输入字符串以字符数组 `char[]` 的形式给出。
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不要给另外的数组分配额外的空间,你必须**原地修改输入数组**、使用 O(1) 的额外空间解决这一问题。
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你可以假设数组中的所有字符都是 [ASCII](https://baike.baidu.com/item/ASCII) 码表中的可打印字符。
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**示例 1:**
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```
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输入:["h","e","l","l","o"]
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输出:["o","l","l","e","h"]
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```
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**示例 2:**
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```
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输入:["H","a","n","n","a","h"]
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输出:["h","a","n","n","a","H"]
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```
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###
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### 题目解析
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这道题没什么难度,直接从两头往中间走,同时交换两边的字符。注意需要白板编程写出来即可,也注意千万别回答一句使用 reverse() 这种高级函数来解决。。。
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### 动画描述
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![](<https://bucket-1257126549.cos.ap-guangzhou.myqcloud.com/blog/ariy2.gif>)
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### 代码实现
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```
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class Solution {
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public:
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string reverseString(string s) {
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int i = 0, j = s.size() - 1;
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while (i < j){
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swap(s[i],s[j]);
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i++;
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j--;
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}
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return s;
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}
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};
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```
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2019-11-14 11:00:28 +08:00
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![](https://blog-1257126549.cos.ap-guangzhou.myqcloud.com/blog/bksj7.png)
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