剑指 Offer 05. 替换空格344. 反转字符串

请实现一个函数，把字符串 s 中的每个空格替换成"%20"。

示例 1：

输入：s = "We are happy."
输出："We%20are%20happy."

class Solution {
    public String replaceSpace(String s) {
        char[] arr=s.toCharArray();
        StringBuilder buid=new StringBuilder();
        for(int i=0;i

344. 反转字符串

难度简单487收藏分享切换为英文接收动态反馈

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 s 的形式给出。

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。

示例 1：

输入：s = ["h","e","l","l","o"]
输出：["o","l","l","e","h"]
示例 2：

输入：s = ["H","a","n","n","a","h"]
输出：["h","a","n","n","a","H"]

class Solution {
    public void reverseString(char[] s) {
        int i=0;
        int j=s.length-1;
        while(i