题解 | #替换空格#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param s string字符串 
     * @return string字符串
     */
    public String replaceSpace (String s) {
        // write code here
        char[] res = new char[s.length()*3];
        int index = 0;
        for(int i = 0;i<s.length();i++){
            if(s.charAt(i) != ' '){
                res[index++] = s.charAt(i); 
            }else{
                res[index++] = '%';
                res[index++] = '2';
                res[index++] = '0';
            }       
        }  
            String str = new String(res,0,index);
            return str;
    }
}