题解 | #统计字符#

import java.util.*;
import java.lang.*;

// 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);
        String[] strs = in.nextLine().split("");
        int letters=0,nums=0,spaces=0,others=0;
        for(String str: strs){
            if(str.matches("[a-zA-Z]")){
                letters++;
            }else if(str.matches("[0-9]")){
                nums++;
            }else if(str.equals(" ")){
                spaces++;
            }else{
                others++;
            }
        }

        System.out.println(letters);
        System.out.println(spaces);
        System.out.println(nums);
        System.out.println(others);
    }
}