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) {
        HashMap<Character, Integer> map = new HashMap<>();
        Scanner input = new Scanner(System.in);
        String s = input.nextLine();
        char[] ch = s.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            map.put(ch[i], (map.getOrDefault(ch[i], 0) + 1));
        }
        Collection<Integer> values = map.values();
        Integer min = Collections.min(values);
        for (Character charater : map.keySet()) {
            if (map.get(charater) == min)
                s = s.replaceAll(String.valueOf(charater), "");
        }
        System.out.println(s);
        input.close();

    }
}