# GCD of digits of a given number

Given a number n, find GCD of its digits.

Examples :

```Input  : 345
Output : 1
GCD of 3, 4 and 5 is 1.

Input  : 2448
Output : 2
GCD of 2, 4, 4 and 8 is 2
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

We traverse the digits of number one by one using below loop

```digit = n mod 10;
n  = n / 10; ```

While traversing digits, we keep track of current GCD and keep updating GCD by finding GCD of current digit with current GCD.

## C++

 `// CPP program to find GCD of digits of a number ` `#include ` `#include ` `using` `namespace` `std; ` ` `  `int` `digitGCD(``int` `n) ` `{ ` `    ``int` `gcd = 0; ` `    ``while` `(n > 0) ` `    ``{         ` `        ``gcd = __gcd(n%10, gcd); ` ` `  `        ``// If at point GCD becomes 1, ` `        ``// return it ` `        ``if` `(gcd == 1) ` `           ``return` `1; ` ` `  `        ``n = n/10; ` `    ``} ` `    ``return` `gcd; ` `} ` ` `  `// driver code ` `int` `main() ` `{ ` `    ``long` `n = 2448; ` `    ``cout << digitGCD(n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to find GCD of digits of a number ` ` `  `class` `GFG ` `{ ` `    ``// Recursive function to return gcd of a and b ` `    ``static` `int` `__gcd(``int` `a, ``int` `b) ` `    ``{  ` `        ``return` `b == ``0` `? a : __gcd(b, a % b);  ` `         `  `    ``} ` `    ``static` `int` `digitGCD(``int` `n) ` `    ``{ ` `        ``int` `gcd = ``0``; ` `        ``while` `(n > ``0``) ` `        ``{      ` `            ``gcd = __gcd(n % ``10``, gcd); ` `     `  `            ``// If at point GCD becomes 1, ` `            ``// return it ` `            ``if` `(gcd == ``1``) ` `            ``return` `1``; ` `     `  `            ``n = n / ``10``; ` `        ``} ` `        ``return` `gcd; ` `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `main (String[] args)  ` `    ``{ ` `        ``int` `n = ``2448``; ` `        ``System.out.print(digitGCD(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by Anant Agarwal. `

## Python3

 `# Python program to find  ` `# GCD of digits of a number ` ` `  `# Recursive function to return gcd of a and b ` `def` `__gcd(a,b): ` `    ``return` `a ``if``(b``=``=``0``) ``else` `__gcd(b, a ``%` `b) ` `     `  `def` `digitGCD(n): ` ` `  `    ``gcd ``=` `0` `    ``while` `(n > ``0``): ` `     `  `        ``gcd ``=` `__gcd(n ``%` `10``, gcd) ` `  `  `        ``# If at point GCD becomes 1, ` `        ``# return it ` `        ``if` `(gcd ``=``=` `1``): ` `           ``return` `1` `  `  `        ``n ``=` `n ``/``/` `10` `     `  `    ``return` `gcd ` ` `  `#Driver code ` `n ``=` `2448` `print``(digitGCD(n)) ` ` `  `# This code is contributed ` `# by Anant Agarwal. `

## C#

 `// C# program to find GCD of ` `// digits of a number ` `using` `System; ` ` `  `class` `GFG { ` `     `  `    ``// Recursive function to return  ` `    ``// gcd of a and b ` `    ``static` `int` `__gcd(``int` `a, ``int` `b) ` `    ``{  ` `        ``return` `b == 0 ? a : __gcd(b, a % b);  ` `         `  `    ``} ` `     `  `    ``static` `int` `digitGCD(``int` `n) ` `    ``{ ` `        ``int` `gcd = 0; ` `        ``while` `(n > 0) ` `        ``{      ` `            ``gcd = __gcd(n % 10, gcd); ` `     `  `            ``// If at point GCD becomes 1, ` `            ``// return it ` `            ``if` `(gcd == 1) ` `            ``return` `1; ` `     `  `            ``n = n / 10; ` `        ``} ` `        ``return` `gcd; ` `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `Main ()  ` `    ``{ ` `        ``int` `n = 2448; ` `        ``Console.Write(digitGCD(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by Nitin Mittal. `

## PHP

 ` 0) ` `    ``{      ` `        ``\$gcd` `= __gcd(``\$n` `% 10, ``\$gcd``); ` ` `  `        ``// If at point GCD  ` `        ``// becomes 1, return it ` `        ``if` `(``\$gcd` `== 1) ` `        ``return` `1; ` ` `  `        ``\$n` `= ``\$n` `/ 10; ` `    ``} ` `    ``return` `\$gcd``; ` `} ` ` `  `// Driver code ` `\$n` `= 2448; ` `echo` `digitGCD(``\$n``); ` ` `  `// This code is contributed by Sam007 ` `?> `

Output :

`2`

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