题解 | 小红书推荐系统

import java.util.*;

// 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);
        Map<String, Integer>map = new HashMap();

        while (in.hasNext()) {

            String str = in.next();
            // System.out.println("读取到" + str);
            if (map.containsKey(str)) {
                map.put(str, map.get(str) + 1);
            } else {
                map.put(str, 1);
            }
        }
        
        List<Map.Entry<String, Integer>>entityList =  new ArrayList(map.entrySet());
        Collections.sort(entityList, new Comparator<Map.Entry<String, Integer>> () {
            @Override
            public int compare(Map.Entry<String, Integer> e1,
                               Map.Entry<String, Integer> e2) {
                if (e1.getValue() == e2.getValue()) {
                    return e1.getKey().compareTo(e2.getKey());
                } else {
                    return e2.getValue() - e1.getValue();
                }
            }
        });
        for (Map.Entry<String, Integer>ans : entityList) {
            if (ans.getValue() >= 3) {
                System.out.println(ans.getKey());
            }
        }
    }
}