LeetCode10.Array and String —Reverse String 字符数组逆置

Posted 2021-12-21 hu-19941213

Write a function that reverses a string. The input string is given as an array of characters char[].

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

You may assume all the characters consist of printable ascii characters.

Example 1:

Input: ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

Input: ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

按题目要求，定义了两个指针，算法简单，无须过多赘述，直接上代码了。

 1 class Solution 
 2 public:
 3 void reverseString(vector<char>& s) 
 4     if(s.size()==0) return ;
 5     int length = s.size();//获取数组长度
 6     char *front = &s[0]; //获取数组第一个元素的地址
 7     char *tail = &s[0];
 8     for (int i = 0,j=length-1; i <=length/2,j>= length / 2;i++,j--)
 9     
10         swap(front[i], tail[j]);
11     
12     front = NULL;
13     tail = NULL;
14 
15 ;