# Check if the given number is divisible by 71 or not

Given a number N, the task is to check whether the number is divisible by 71 or not.

Examples:

Input: N = 25411681
Output: yes
Explanation:
71 * 357911 = 25411681

Input: N = 5041
Output: yes
Explanation:
71 * 71 = 5041

Approach: The divisibility test of 71 is:

1. Extract the last digit.
2. Subtract 7 * last digit from the remaining number obtained after removing the last digit.
3. Repeat the above steps until a two-digit number, or zero, is obtained.
4. If the two-digit number is divisible by 71, or it is 0, then the original number is also divisible by 71.

For example:

```If N = 5041

Step 1:
N = 5041
Last digit = 1
Remaining number = 504
Subtracting 7 times last digit
Resultant number = 504 - 7*1 = 497

Step 2:
N = 497
Last digit = 7
Remaining number = 49
Subtracting 7 times last digit
Resultant number = 49 - 7*7 = 0

Step 3:
N = 0
Since N is a two-digit number,
and 0 is divisible by 71

Therefore N = 5041 is also divisible by 71```

Below is the implementation of the above approach:

## C++

 `// C++ program to check whether a number``// is divisible by 71 or not``#include``#include` `using` `namespace` `std;` `// Function to check if the number is divisible by 71 or not ``bool` `isDivisible(``int` `n) ``{``    ``int` `d;``    ``// While there are at least two digits ``    ``while` `(n / 100) ``    ``{` `        ``// Extracting the last ``        ``d = n % 10;` `        ``// Truncating the number ``        ``n /= 10;` `        ``// Subtracting seven times the last ``        ``// digit to the remaining number ``        ``n = ``abs``(n - (d * 7));``    ``}``    ``// Finally return if the two-digit``    ``// number is divisible by 71 or not``    ``return` `(n % 71 == 0) ;``}` `// Driver Code ``int` `main() {``    ``int` `N = 5041;` `    ``if` `(isDivisible(N)) ``        ``cout << ``"Yes"` `<< endl ;``    ``else``        ``cout << ``"No"` `<< endl ;``    ` `    ``return` `0;     ``} ` `// This code is contributed by ANKITKUMAR34`

## Java

 `// Java program to check whether a number``// is divisible by 71 or not``import` `java.util.*;` `class` `GFG{` `// Function to check if the number is divisible by 71 or not ``    ``static` `boolean` `isDivisible(``int` `n) ``    ``{``        ``int` `d;``        ``// While there are at least two digits ``        ``while` `((n / ``100``) <=``0``)``        ``{``    ` `            ``// Extracting the last ``            ``d = n % ``10``;``    ` `            ``// Truncating the number ``            ``n /= ``10``;``    ` `            ``// Subtracting seven times the last ``            ``// digit to the remaining number ``            ``n = Math.abs(n - (d * ``7``));``        ``}` `        ``// Finally return if the two-digit``        ``// number is divisible by 71 or not``        ``return` `(n % ``71` `== ``0``) ;``    ``}``    ` `    ``// Driver Code ``    ``public` `static` `void` `main(String args[]){``        ``int` `N = ``5041``;``    ` `        ``if` `(isDivisible(N)) ``            ``System.out.println(``"Yes"``) ;``        ``else``            ``System.out.println(``"No"``);``    ``} ``}` `// This code is contributed by AbhiThakur`

## Python 3

 `# Python program to check whether a number``# is divisible by 71 or not` `# Function to check if the number is ``# divisible by 71 or not ``def` `isDivisible(n) : ` `    ``# While there are at least two digits ``    ``while` `n ``/``/` `100` `: ` `        ``# Extracting the last ``        ``d ``=` `n ``%` `10` `        ``# Truncating the number ``        ``n ``/``/``=` `10` `        ``# Subtracting seven times the last ``        ``# digit to the remaining number ``        ``n ``=` `abs``(n``-``(d ``*` `7``))` `    ``# Finally return if the two-digit``    ``# number is divisible by 71 or not``    ``return` `(n ``%` `71` `=``=` `0``) ` `# Driver Code ``if` `__name__ ``=``=` `"__main__"` `: ``    ` `    ``N ``=` `5041` `    ``if` `(isDivisible(N)) : ``        ``print``(``"Yes"``) ``    ``else` `: ``        ``print``(``"No"``) `

## C#

 `// C# program to check whether a number``// is divisible by 71 or not``using` `System; ``        ` `class` `GFG ``{ ``    ` `// Function to check if the number is divisible by 71 or not ``static` `bool` `isDivisible(``int` `n) ``{``    ``int` `d;``    ``// While there are at least two digits ``    ``while` `(n / 100 > 0) ``    ``{``    ` `        ``// Extracting the last ``        ``d = n % 10;``    ` `        ``// Truncating the number ``        ``n /= 10;``    ` `        ``// Subtracting fourteen times the last ``        ``// digit to the remaining number ``        ``n = Math.Abs(n - (d * 7));``    ``}``    ` `    ``// Finally return if the two-digit``    ``// number is divisible by 71 or not``    ``return` `(n % 71 == 0);``}``    ` `// Driver Code ``public` `static` `void` `Main() ``{ ``    ``int` `N = 5041;``    ` `    ``if` `(isDivisible(N)) ``        ``Console.WriteLine(``"Yes"``);``    ``else``        ``Console.WriteLine(``"No"``);``} ``} ` `// This code is contributed by mohit kumar 29. `

## Javascript

 ``

Output:
`Yes`

Time Complexity: O(log10N)

Auxiliary Space: O(1)

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