题解 | #统计字符#简单循环

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);

        String input = in.nextLine();
        int[] stat = new int[4];
        for (int i = 0; i < input.length(); i++) {
            char c = input.charAt(i);
            if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
                ++stat[0];
            else if (c == ' ')
                ++stat[1];
            else if (c >= '0' && c <= '9')
                ++stat[2];
            else
                ++stat[3];
        }
        for (int i = 0; i < 4; i++) {
            System.out.println(stat[i]);
        }
    }
}