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 sc = new Scanner(System.in);
        String str = sc.nextLine();
        int iL = 0;
        int iD = 0;
        int iS = 0;
        int iO = 0;
        for (int i = 0; i < str.length(); i++) {
            if (Character.isLetter(str.charAt(i))) {
                iL++;
            } else if (str.charAt(i) == ' ') {
                iS++;
            } else if (Character.isDigit(str.charAt(i))) {
                iD++;

            } else {
                iO++;
            }

        }

        System.out.println(iL + "\n" + iS + "\n" + iD + "\n" + iO);
    }
}