题面

核心思想

map记录String的出现次数

set去重+自定义排序

代码

import java.util.*;
import java.util.function.Function;

public class Main {

    public static void main(String[] args) {
        final long MOD = (long) (1e9 + 7);
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        String[] s1 = s.split(" ");
        HashMap<String,Integer> v= new HashMap<>();
        
        //统计次数
        for(String ss: s1){
            v.put(ss, v.getOrDefault(ss, 0) + 1);
        }
        TreeSet<String> st = new TreeSet<>(new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                int cnt1 = v.get(o1);
                int cnt2 = v.get(o2);
                if(cnt1 != cnt2) {
                    return cnt2 - cnt1; // 按次数从大到小排序
                }else {
                    return o1.compareTo(o2);// 字典升序
                }
            }
        });
        for(String ss: s1){
            if(v.get(ss) >= 3) {
                st.add(ss);
            }
        }
        
        
        for(String ss: st)
            System.out.println(ss);
    }
}