替换空格_JAVA_较难

• 遍历替换

public class Solution {
    public String replaceSpace(StringBuffer str) {
        StringBuffer res = new StringBuffer();
        for(char c : str.toString().toCharArray()) {
            if(c == ' ') {
                res.append("%20");
            } else {
                res.append(c);
            }
        }
        return res.toString();
    }
}