题解 | #统计字符#

import java.util.Scanner;

// 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);
        
        while (in.hasNextLine()) { 
            String str = in.nextLine();
            int letter=0;
            int blank=0;
            int number=0;
            int other=0;

            for(int i=0;i<str.length();i++){
                char ch = str.charAt(i);
                if(ch>='a'&& ch<='z'|| ch>='A'&&ch<='Z'){
                    letter++;
                }else if(ch==' '){
                    blank++;
                }else if(ch>='0'&& ch<='9'){
                    number++;
                }else{
                    other++;
                }
            }
            System.out.println(letter);
            System.out.println(blank);
            System.out.println(number);
            System.out.println(other);
        }
    }
}