题解 | #删除字符串中出现次数最少的字符#哈希表破解

import java.util.*;

// 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 str = in.nextLine();
        Map<Character, Integer> map = new HashMap<>();
        int min = 21;
        for (int i = 0; i < str.length(); i++) {
            int count = 0;
            char c = str.charAt(i);
            if (map.containsKey(c)) {
                count = map.get(c) + 1;
            } else {
                count = 1;
            }
            map.put(c, count);
        }
        for (Integer i : map.values()) {
            if (min > i) {
                min = i;
            }
        }
        for (Character c : map.keySet()) {
            if (map.get(c) == min) {
                String []arr = str.split(c.toString());
                str = new String(arr[0] + arr[1]);
            }
        }
        System.out.print(str);
    }
}