题解 | HJ_23 #删除字符串中出现次数最少的字符#

import java.util.List;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

// 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);
        String input = in.nextLine();

        Map<Character, Integer> countMap = new HashMap<>();
        char[] chars = input.toCharArray();
        for (char c : chars) {
            countMap.put(c, countMap.getOrDefault(c, 0) + 1);
        }

        //找到出现次数最少的的字符
        int minCount = countMap.values().stream().sorted().findFirst().get();
        List<Character> removeChars = new ArrayList();
        countMap.entrySet().stream().forEach(entry -> {
            if (entry.getValue() == minCount) {
                removeChars.add(entry.getKey());
            }
        });

        //
        for (char c : chars) {
            if (!removeChars.contains(c)) {
                System.out.print(c);
            }
        }
        System.out.println();
    }
}