Blue Bridge Cup: Clean number (use string to make, super simple!)

topic

[Problem description]
   Xiao Ming dislikes the number 2 very much, including those that contain the number 2 in the digits. If the digits of a number do not contain the number 2, Xiao Ming calls it a clean number.
   How many clean numbers are there among the integers 1 to n?
[Input format]
   The first line of input contains an integer n.
[Output format] The
   output line contains an integer to indicate the answer.
[Sample input]
30
[Sample output]
   18
[Evaluation use case scale and conventions]
   For 40% of evaluation use cases, 1 <= n <= 10000.
   For 80% of the test cases, 1 <= n <= 100000.
   For all measurement cases, 1 <= n <= 1000000.

Problem solving ideas

   Convert a number of type int to a string of type String, and then use the contains method of the string to determine whether the string contains "2". If it does, it is not a clean number, and vice versa, count++.

hint

  The contains method of a string determines whether it contains a string , and the double quotes cannot be dropped

Code

import java.util.Scanner;

public class Main {
    
    //蓝桥杯要求class命名为Main，且无package
    public static void main(String[] args) {
    
    
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int count = 0;
        for(int i=1;i<=n;i++){
    
    
            String str = i+"";//转为字符串
            if(str.contains("2")){
    
    
                continue;//不为洁净数continue结束当前for循环
            }
            count++;//为洁净数则count++
        }
        System.out.println(count);
    }
}