题解 | #字符统计#--J8-map按值降序后按key升序

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        char[] chrs = str.toCharArray();
        Map<Character, Integer> count = new HashMap<>();
        for (char chr : chrs) {
            if (count.containsKey(chr)) {
                count.put(chr, count.get(chr) + 1);
            } else {
                count.put(chr, 1);
            }
        }
        // java8-map按值降序然后按key升值排序
        count.entrySet().stream()
        .sorted(Map.Entry.<Character, Integer>comparingByValue()
        .reversed().thenComparing(Map.Entry :: getKey))
        .map(Map.Entry :: getKey).forEach(item -> System.out.print(item.charValue()));
    }
}