题解 | #合唱队#

package 华为.字符串;
//用HashMap的去重就能实现
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class 字符个数统计 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //输入字符串
        String s = sc.nextLine();
        //统计不同的字符个数
        System.out.println(calue(s));
    }

    private static int calue(String s) {
        char[] chs = s.toCharArray();
        int len = s.length();
        Map<Character, Integer> map = new HashMap<>();
        for (int i = 0; i < len; i++) {
            char ch = chs[i];
            if (!map.containsKey(ch)) {
                map.put(ch, 1);
            }
        }
        return map.size();
    }
}