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."
输入:s = "We are happy."
输出:"We%20are%20happy."
class Solution { public: string replaceSpace(string s) { string ans; for (char ch : s) { if (ch == ' ') ans += "%20"; else ans += ch; } return ans; } };