Java解 | #HJ10字符个数（种类）统计#

import java.util.Scanner;
import java.util.HashSet;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            String str = in.nextLine();
            HashSet<Integer> set = new HashSet<>();
            for(int i=0;i<str.length();i++){
                char[] chars = str.toCharArray();
                int c = (int)chars[i];
                if(c >= 0 && c <= 127){
                    set.add(c);
                }
            }
            System.out.println(set.size());
        }
    }    
}