题解 | #删除字符串中出现次数最少的字符#

API调用工程师来了。。。采用流进行排序解决关键序列问题

import java.util.*;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args){
        Scanner s = new Scanner(System.in);
        String line = s.nextLine();
        char[] chars = line.toCharArray();
        HashMap<Character,Integer> map = new HashMap<>();
        for (char aChar : chars) {
            Integer integer = map.get(aChar);
            if (null != integer){
                map.put(aChar,integer+1);
                continue;
            }
            map.put(aChar,1);
        }
        Set<Map.Entry<Character, Integer>> entries = map.entrySet();
        List<Map.Entry<Character, Integer>> collect = entries.stream().sorted(Comparator.comparingInt(Map.Entry::getValue)).collect(Collectors.toList());
        int less = 0;
        for (Map.Entry<Character, Integer> entry : collect) {
            if (less == 0) {
                less = entry.getValue();
            }
            if (entry.getValue() > less){
                break;
            }
            line= line.replace(String.valueOf(entry.getKey()), "");
        }
        System.out.println(line);
    }
}