【剑指 Offer 05. 替换空格】

请实现一个函数，

示例 1：

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

class Solution {
    public String replaceSpace(String s) {
        return s.replace(" ","%20");
    }
}

class Solution {
    public String replaceSpace(String s) {
        StringBuilder sb = new StringBuilder();
        for(int i = 0;i