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 scanner = new Scanner(System.in);
        String content = scanner.nextLine();

        int letterNum = 0;
        int blankNum = 0;
        int digitalNum = 0;
        int otherNum = 0;
        for (char c : content.toCharArray()) {
            if (Character.isLetter(c)) {
                letterNum++;
            } else if (' ' == c) {
                blankNum++;
            } else if (c >= '0' && c <= '9') {
                digitalNum++;
            } else {
                otherNum++;
            }
        }
        System.out.println(letterNum);
        System.out.println(blankNum);
        System.out.println(digitalNum);
        System.out.println(otherNum);
    }
}