题解 | #删除字符串中出现次数最少的字符#

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

public class Main {
   public static void main(String[] args) {
      Scanner scanner = new Scanner(System.in);
      String s = scanner.next();
      char[] chars = s.toCharArray();
      HashMap<Character, Integer> map = new HashMap<>();
      for (char c : chars){
         map.put(c, map.getOrDefault(c, 0) +1);
      }
      int min = Integer.MAX_VALUE;
      for (Map.Entry<Character, Integer> a : map.entrySet()){
         Integer value = a.getValue();
         if(value < min){
            min = Math.min(value, min);
         }
      }
       StringBuilder sb = new StringBuilder();
       for(char ch : chars){
           if(map.get(ch) != min){
               sb.append(ch);
           }
       }
      System.out.println(sb.toString());
   }
}