题解 | #表示数字#

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 str = in.nextLine();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i) >= '0' && str.charAt(i) <= '9') {
                int j = i;
                sb.append("*");
                while (j < str.length() && str.charAt(j) >= '0' && str.charAt(j) <= '9') {
                    sb.append(str.charAt(j++));
                }
                sb.append("*");
                i = j - 1;
            } else {
                sb.append(str.charAt(i));
            }
        }
        System.out.print(sb);
    }
}