编辑代码

import java.util.*;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        String[] strings = s.split(",");
        String[] s1 = strings[0].split(" ",-1);
        StringBuffer sb = new StringBuffer();
        for (int i = s1.length-1; i >= 0 ; i--) {
            sb.append(changeCase(s1[i]));
            if(i == 0){
                break;
            }
            sb.append(" ");
        }
        System.out.println(sb.toString());
    }
    
    public static String changeCase(String s){
        StringBuffer sb = new StringBuffer();
        for(char c:s.toCharArray()){
           if(Character.isUpperCase(c)){
               sb.append(Character.toLowerCase(c));
           }else{
                sb.append(Character.toUpperCase(c));
            }
        }
        return sb.toString();
    }
}