题解 | #字符串变形#

import java.util.*;

public class Solution {
    public String trans(String s, int n) {
    // 解题步骤
    // 1、先翻转遍历，将小写转换成大写，大写转化为小写
    // 2、遍历步骤1生成的，遇到空格，再翻转单个单词，存入得到StringBuffer
          //返回值：
        //"SAMPLE A IS tHIS"
        // String s = "This is a sample";
        // int n = 16;
        StringBuffer  recv = new StringBuffer();
        // 翻转 + 转行大小写
        for(int i = n - 1;i >= 0;i--){
            char c = (char)s.charAt(i);
            if(c >= 'a' && c <= 'z'){
                c = (char)(c - 32);
            }else if(c >= 'A' && c <= 'Z'){
                c = (char)(c + 32);
            }
            recv.append(c);
        }
        //System.out.println(recv.toString());
        StringBuffer recvBuffer = new StringBuffer();
        for(int i = 0;i < n; i++){
            String temp = "";
            char c;
            while(i < n && (c = recv.charAt(i)) != ' '){
                temp += c;
                i++;
            }
            //System.out.println(temp);
            StringBuffer buffer = new StringBuffer(temp);
            temp = buffer.reverse().toString();
            recvBuffer.append(temp);
            if(i -1 != n-1){
                recvBuffer.append(" ");
            }
        }

        return recvBuffer.toString();
    }
}