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Check Whether a number is Duck Number or not
• Difficulty Level : Basic
• Last Updated : 13 Apr, 2021

A Duck number is a positive number which has zeroes present in it, For example 3210, 8050896, 70709 are all Duck numbers. Please note that a numbers with only leading 0s is not considered as Duck Number. For example, numbers like 035 or 0012 are not considered as Duck Numbers. A number like 01203 is considered as Duck because there is a non-leading 0 present in it.

Examples :

Input : 707069
Output : It is a duck number.
Explanation: 707069 does not contains zeros at the beginning.

Input : 02364
Output : It is not a duck number.
Explanation: in 02364 there is a zero at the beginning of the number.

## C++

 `// C++ Program to check whether``// a number is Duck Number or not.``#include ``using` `namespace` `std;` `// Function to check whether``// given number is duck number or not.``bool` `check_duck(string num)``{``    ``// Ignore leading 0s``    ``int` `i = 0, n = num.length();``    ``while` `(i < n && num[i] == ``'0'``)``        ``i++;` `    ``// Check remaining digits``    ``while` `(i < n) {``        ``if` `(num[i] == ``'0'``)``            ``return` `true``;``        ``i++;``    ``}` `    ``return` `false``;``}` `// Driver Method``int` `main(``void``)``{``    ``string num = ``"1023"``;``    ``if` `(check_duck(num))``        ``cout << ``"It is a duck number\n"``;``    ``else``        ``cout << ``"It is not a duck number\n"``;` `    ``return` `0;``}`

## Java

 `// Java Program to check whether a``// number is Duck Number or not.` `import` `java.io.*;``class` `GFG {` `    ``// Function to check whether``    ``// the given number is duck number or not.``    ``static` `boolean` `check_duck(String num)``    ``{``        ``// Ignore leading 0s``        ``int` `i = ``0``, n = num.length();``        ``while` `(i < n && num.charAt(i) == ``'0'``)``            ``i++;` `        ``// Check remaining digits``        ``while` `(i < n) {``            ``if` `(num.charAt(i) == ``'0'``)``                ``return` `true``;``            ``i++;``        ``}` `        ``return` `false``;``    ``}` `    ``// Driver Method``    ``public` `static` `void` `main(String args[]) ``throws` `IOException``    ``{``        ``String num = ``"1023"``;``        ``if` `(check_duck(num))``            ``System.out.println(``"It is a duck number"``);``        ``else``            ``System.out.println(``"It is not a duck number"``);``    ``}``}`

## Python

 `# Python program to check whether a number is Duck Number or not.` `# Function to check whether``# the given number is duck number or not.``def` `check_duck(num) :` `    ``# Length of the number(number of digits)``    ``n ``=` `len``(num)``   ` `    ``# Ignore leading 0s``    ``i ``=` `0``    ``while` `(i < n ``and` `num[i] ``=``=` `'0'``) :``        ``i ``=` `i ``+` `1` `    ``# Check remaining digits``    ``while` `(i < n) :``        ``if` `(num[i] ``=``=` `"0"``) :``            ``return` `True``        ``i ``=` `i ``+` `1` `    ``return` `False``    `  `# Driver Method``num1 ``=` `"1023"``if``(check_duck(num1)) :``    ``print` `"It is a duck number"``else` `:``    ``print` `"It is not a duck number"` `# Write Python3 code here`

## C#

 `// C# Program to check whether a``// number is Duck Number or not.``using` `System;` `class` `GFG {``    ` `    ``// Function to check whether``    ``// the given number is duck``    ``// number or not.``    ``static` `bool` `check_duck( String num)``    ``{``        ` `        ``// Ignore leading 0s``        ``int` `i = 0, n = num.Length;``        ``while` `(i < n && num[i] == ``'0'``)``            ``i++;` `        ``// Check remaining digits``        ``while` `(i < n) {``            ``if` `(num[i] == ``'0'``)``                ``return` `true``;``            ``i++;``        ``}` `        ``return` `false``;``    ``}``    `  `    ``// Driver Method``    ``public` `static` `void` `Main()``    ``{``        ` `        ``String num1 = ``"1023"``;``        ` `        ``// checking number1``        ``if``( check_duck(num1))``            ``Console.Write(``"It is a "``                      ``+ ``"duck number"``);``        ``else``            ``Console.Write(``"It is not "``                    ``+ ``"a duck number"``);``    ``}``}` `// This code is contributed by``// nitin mittal.`

## Javascript

 ``

Output :

`It is a duck number.`

This article is contributed by Nikita Tiwari. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
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