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);
        // 注意 hasNext 和 hasNextLine 的区别
        // while (in.hasNextInt()) { // 注意 while 处理多个 case
        //     int a = in.nextInt();
        //     int b = in.nextInt();
        //     System.out.println(a + b);
        // }
        String line = in.nextLine();
        int len = line.length();
        int[] count = new int[4];
        for (int i = 0; i < len; i++) {
            char c = line.charAt(i);
            if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
                count[0]++;
            } else if ((c >= '0' && c <= '9') ) {
                count[2]++;
            } else if (c == ' ') {
                count[1]++;
            } else {
                count[3]++;
            }
        }
        for (int i = 0; i < 4; i++) {
            System.out.println(count[i]);
        }
    }
}