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# Check if Decimal representation of an Octal number is divisible by 7

• Last Updated : 06 Apr, 2021

Given an Octal number N. The task is to write a program to check if the Decimal representation of the given octal number N is divisible by 7 or not.
Examples

```Input: N = 112
Output: NO
Equivalent Decimal = 74
7410 = 7 * 10 1 + 4 * 100
1128 = 1 * 82 + 1 * 81 + 2 * 80

Input: N = 25
Output: YES
Decimal Equivalent = 21```

The idea is to note that, 8 % 7 will return 1. Thus, when we expand octal representation and take its modulo 7 all powers of 8 in individual terms will reduce to 1. So, if the sum of all the digits in octal representation is divisible by 7 then, the corresponding decimal number will be divisible by 7.
Below is the implementation of the above approach:

## C++

 `// CPP program to check if Decimal representation``// of an Octal number is divisible by 7 or not` `#include ``using` `namespace` `std;` `// Function to check Divisibility``int` `check(``int` `n)``{``    ``int` `sum = 0;` `    ``// Sum of all individual digits``    ``while` `(n != 0) {``        ``sum += n % 10;``        ``n = n / 10;``    ``}` `    ``// Condition``    ``if` `(sum % 7 == 0)``        ``return` `1;``    ``else``        ``return` `0;``}` `// Driver Code``int` `main()``{``    ``// Octal number``    ``int` `n = 25;` `    ``(check(n) == 1) ? cout << ``"YES"``                    ``: cout << ``"NO"``;` `    ``return` `0;``}`

## Java

 `// Java program to check if Decimal``// representation of an Octal number``// is divisible by 7 or not``import` `java.util.*;``import` `java.lang.*;``import` `java.io.*;` `class` `GFG``{``    ` `// Function to check Divisibility``static` `int` `check(``int` `n)``{``    ``int` `sum = ``0``;` `    ``// Sum of all individual digits``    ``while` `(n != ``0``)``    ``{``        ``sum += n % ``10``;``        ``n = n / ``10``;``    ``}` `    ``// Condition``    ``if` `(sum % ``7` `== ``0``)``        ``return` `1``;``    ``else``        ``return` `0``;``}` `// Driver Code``public` `static` `void` `main(String args[])``{``    ``// Octal number``    ``int` `n = ``25``;` `    ``String s=(check(n) == ``1``) ?``                       ``"YES"` `: ``"NO"``;``    ``System.out.println(s);``}``}` `// This code is contributed``// by Subhadeep`

## Python 3

 `# Python 3 program to check if``# Decimal representation of an``# Octal number is divisible by``# 7 or not` `# Function to check Divisibility``def` `check(n):` `    ``sum` `=` `0` `    ``# Sum of all individual digits``    ``while` `n !``=` `0` `:``        ``sum` `+``=` `n ``%` `10``        ``n ``=` `n ``/``/` `10` `    ``# Condition``    ``if` `sum` `%` `7` `=``=` `0` `:``        ``return` `1``    ``else``:``        ``return` `0` `# Driver Code``if` `__name__ ``=``=` `"__main__"``:``    ``# Octal number``    ``n ``=` `25` `    ``print``((``"YES"``) ``if` `check(n) ``=``=` `1``                  ``else` `print``(``"NO"``))` `# This code is contributed``# by ChitraNayal`

## C#

 `// C# program to check if Decimal``// representation of an Octal``// number is divisible by 7 or not``using` `System;` `class` `GFG``{``    ` `    ``// Function to check Divisibility``    ``static` `int` `check(``int` `n)``    ``{``            ``int` `sum = 0;``    ` `        ``// Sum of all individual digits``        ``while` `(n != 0)``        ``{``            ``sum += n % 10;``            ``n = n / 10;``        ``}``    ` `    ``// Condition``    ``if` `(sum % 7 == 0)``        ``return` `1;``    ``else``        ``return` `0;``}` `// Driver Code``public` `static` `void` `Main(String []args)``{``    ``// Octal number``    ``int` `n = 25;``    ` `    ``String s=(check(n) == 1) ?``                       ``"YES"` `: ``"NO"``;``    ``Console.WriteLine(s);``}``}` `// This code is contributed``// by Kirti_Mangal`

## PHP

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## Javascript

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Output:
`YES`

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