题解 | #字符个数统计#

import java.util.HashSet; import java.util.Scanner;

public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String str = scanner.next(); char[] chars = str.toCharArray(); int count = 0; HashSet set = new HashSet<>(); for (int i = 0; i < chars.length; i++) { boolean b = set.add(chars[i] + ""); if(b){ ++count; } } System.out.println(count); } }