题解 | #汽水瓶#

```import java.util.*;
public class Main {
        public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str=sc.nextLine();
        HashMap<Character,Integer> map=new HashMap<>();
        char tmp;
        for (int i = 0; i <str.length() ; i++) {
            //通过charAt(),进行获取字符串的值
            tmp= str.charAt(i);
            //判断这个tmp是否已经在map中
            if (map.containsKey(tmp)){
                //存在的话就用value+1
                map.put(tmp,map.get(tmp)+1);
            }else {
                map.put(tmp,1);
            }
        }
        int least = least(map);//获取了出现次数最小的数字
        for (Character key : map.keySet()) {
            if (map.get(key) == least){
                str = str.replaceAll(Character.toString(key), "");
            }
        }
        System.out.println(str);
        sc.close();
    }
    //再写一个方法，计算Map的最小值
    public static int least(HashMap<Character,Integer> map){
        //获取map的值，放在数组中
        HashSet<Integer> set = new HashSet<>();
        //把出现的次数存到集合中
        for (Character key:map.keySet()){ 
            set.add(map.get(key));
        }
        return Collections.min(set);
    }
}