题解 | #字符串变形#

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 
     * @param n int整型 
     * @return string字符串
     */
    public String trans (String s, int n) {
        String[] strs = s.split(" ");
        StringBuffer res = new StringBuffer(); 
        
        for(int i = strs.length - 1; i >= 0; i--){
            res.append(transform(strs[i]));
            if(i != 0)
                res.append(" ");
        }
        while(n > res.length()){
            res.insert(0, " ");
        }

        return res.toString();
    }
    private String transform(String str){
        StringBuffer sb =  new StringBuffer();
        for(int i = 0; i < str.length(); i++){
            char ch = str.charAt(i);
            if(ch <= 'z' && ch >= 'a' )
                sb.append((char)(ch - (97 - 65)));
            else
                sb.append((char)(ch + (97 - 65)));
        }
        return sb.toString();
    }
}