Duck_Number.java

// Duck number is another special positive non-zero number that contains zero in
// it. The digit zero should not be presented at the starting of the number.
// Zero can be present at any of the positions except the beginning of the
// number.

// Let's understand some examples of Duck numbers.

// 3210 is a Duck number because it contains zero at the end of the number but
// not present at the beginning of it.
// 08237 is not a Duck number because it contains zero at the beginning of it.
// 7033 is a Duck number because it contains zero at the second position, not at
// the beginning.
// 030405 is not a Duck number because it also contains zero in starting of the
// number.
// 00153 is also not a Duck number because it contains leading zeros.
// These are the following steps that we use to check whether the given number
// is a Duck number or not.

// We first take a number.
// We then find the last digit of the number.
// If the last digit is zero, it is a Duck number.
// Otherwise, we remove that digit from the number.
// Perform steps 2, 3, and 4 until the number becomes zero.
// Let's implement the code to check a valid Duck number.

//import required classes and packages  
import java.util.*;   
import java.io.*;   
import java.util.Scanner;  
  
 class Duck_Number {  
  
   // create checkNumber() method that returns true when it founds number Buzz   
   public static boolean checkNumber(int number) {  
  
      // use loop to repeat steps  
      while(number != 0) {  
  
         // check whether the last digit of the number is zero or not  
         if(number%10 == 0)  
            return true;    //return true if the number is Duck  
  
         // divide the number by 10 to remove the last digit  
         number = number / 10;  
      }  
  
      return false; //return false if the number is not Duck  
   }  
       // main() method start  
    public static void main(String args[])   
    {     
        int n1, n2;  
          
        //create scanner class object to get input from user  
        Scanner sc=new Scanner(System.in);  
          
        //show custom message  
        System.out.println("Enter first number");  
          
        //store user entered value into variable n1  
        n1 = sc.nextInt();  
          
        //show custom message  
        System.out.println("Enter second number");  
          
        //store user entered value into variable n2  
        n2 = sc.nextInt();  
          
        if (checkNumber(n1))   
            System.out.println(n1 + " is a Duck number");   
        else  
            System.out.println(n1 + " is not a Duck number");   
        if (checkNumber(n2))   
            System.out.println(n2 + " is a Duck number");   
        else  
            System.out.println(n2 + " is not a Duck number");   
    }  
}