题解 | #字符个数统计#

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

public class Main {
    public static void main(String[] args) {
        //思路：map去重 再求不重复个数
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        char[] chars = str.toCharArray();
        int length = chars.length;
        //System.out.println(chars);
        Map<Integer,Character> map = new HashMap<>();
        for (int i=0; i<length ; i++){
            if (map.containsValue(chars[i])) continue;
            else map.put(i,chars[i]);
        }
        System.out.println(map.size());
    }
}