题解 | #小红的字符串构造#

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        String s = in.nextLine();
        char[] init = s.toCharArray();
    
        Set<Character> set = new HashSet<>();
        StringBuilder sb = new StringBuilder();
        for(char a : init){
                if(!set.contains(a)){
                set.add(a);
                sb.append(a);
                }}
            char[] c =sb.toString().toCharArray();
            if(c.length==1){System.out.print(-1);}
        else{
            Map<Character,Character> map = new HashMap<>();
            for(int i= 0;i<c.length;i++){
                char old=c[i];
                char newChar=c[(i+1)%c.length];
                map.put(old,newChar);
            }
            StringBuilder xx = new StringBuilder();
            for(int i=0;i<init.length;i++){
                char z = map.get(init[i]);
                xx.append(z);
            }
            System.out.print(xx.toString());}
        
    }
}