LeetCode--面试题05. 替换空格

方法1：库函数

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

方法2：

class Solution {
    public String replaceSpace(String s) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == ' ') {
                sb.append("%20");
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }
}