题解 | #删除字符串中出现次数最少的字符#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        Map<Character,Integer> map = new HashMap<>();
        String s = in.next();
        for(int i = 0; i<s.length(); i++){
            if(!map.containsKey(Character.valueOf(s.charAt(i)))){
                map.put(Character.valueOf(s.charAt(i)),1);
            }else{
                map.put(Character.valueOf(s.charAt(i)),map.get(Character.valueOf(s.charAt(i)))+1);
            }
        }
        Collection<Integer> c = map.values();
        Integer min = Collections.min(c);                   
        for(int i = 0; i<s.length(); i++){
            if(map.get(Character.valueOf(s.charAt(i)))>min){
                System.out.print(Character.valueOf(s.charAt(i)));
            }
        }
    }
}