题解 | #删除字符串中出现次数最少的字符#

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 scanner = new Scanner(System.in);
        String string = scanner.nextLine();
        char[] chr = string.toCharArray();
        HashMap<Character, Integer> hashMap = new HashMap<>();
        for (char c : chr) {
            hashMap.put(c, hashMap.getOrDefault(c, 0) + 1);
        }
        ArrayList<Map.Entry<Character, Integer>> list = new ArrayList<>(hashMap.entrySet());
        list.sort(new Comparator<Map.Entry<Character, Integer>>() {
            @Override
            public int compare(Map.Entry<Character, Integer> o1, Map.Entry<Character, Integer> o2) {
                return o2.getValue().compareTo(o1.getValue());
            }
        });
        String modifiedStrings = string;
        for (int i = list.size() - 1; i >= 0; i--) {
            char character = list.get(i).getKey();
            modifiedStrings = modifiedStrings.replace(String.valueOf(character), "");
            if (!list.get(i - 1).getValue().equals(list.get(i).getValue())) {
                break;
            }
        }
        System.out.println(modifiedStrings);
    }
}