# Largest Even and Odd N-digit numbers in Octal Number System

Given an integer N, the task is to find the largest even and odd N-digit numbers in Octal Number System.

Examples:

Input: N = 4
Output:
Even : 7776
Odd : 7777

Input: N = 2
Output:
Even : 76
Odd : 77

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

Approach: To get the largest number, the digits of the number have to be maximum possible. Since in the octal number system, the maximum digit is ‘7’. So, generate ‘7’ (N – 1) times and then append ‘6’ for even and ‘7’ for odd in the end.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to print the largest n-digit even ` `// and odd numbers in octal number system ` `void` `findNumbers(``int` `n) ` `{ ` ` `  `    ``// Append '7' (N - 1) times ` `    ``string ans = string(n - 1, ``'7'``); ` ` `  `    ``// Append '6' for an even number ` `    ``string even = ans + ``'6'``; ` ` `  `    ``// Append '7' for an odd number ` `    ``string odd = ans + ``'7'``; ` ` `  `    ``cout << ``"Even : "` `<< even << endl; ` `    ``cout << ``"Odd : "` `<< odd << endl; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `n = 4; ` ` `  `    ``findNumbers(n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java implementation of the approach ` `class` `GFG  ` `{ ` ` `  `// Function to print the largest n-digit even ` `// and odd numbers in octal number system ` `static` `void` `findNumbers(``int` `n) ` `{ ` ` `  `    ``// Append '7' (N - 1) times ` `    ``String ans = ``""``; ` `    ``for` `(``int` `i = ``0``; i < n - ``1``; i++) ` `        ``ans += ``'7'``; ` ` `  `    ``// Append '6' for an even number ` `    ``String even = ans + ``'6'``; ` ` `  `    ``// Append '7' for an odd number ` `    ``String odd = ans + ``'7'``; ` ` `  `    ``System.out.println(``"Even : "` `+ even); ` `    ``System.out.println(``"Odd : "` `+ odd); ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String args[])  ` `{ ` `    ``int` `n = ``4``; ` ` `  `    ``findNumbers(n); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

## Python3

 `# Python3 implementation of the approach ;  ` ` `  `# Function to print the largest n-digit even  ` `# and odd numbers in octal number system  ` `def` `findNumbers(N) : ` ` `  `    ``# Append '7' (N - 1) times  ` `    ``ans ``=` `'7'` `*` `(N ``-` `1``) ` ` `  `    ``# Append '6' for an even number  ` `    ``even ``=` `ans ``+` `'6'``;  ` ` `  `    ``# Append '7' for an odd number  ` `    ``odd ``=` `ans ``+` `'7'``;  ` ` `  `    ``print``(``"Even : "``, even);  ` `    ``print``(``"Odd : "``, odd );  ` ` `  `# Driver code  ` `if` `__name__ ``=``=` `"__main__"` `:  ` ` `  `    ``n ``=` `4``;  ` ` `  `    ``findNumbers(n);  ` ` `  `# This code is contributed by AnkitRai01 `

## C#

 `// C# implementation of the approach ` `using` `System; ` `     `  `class` `GFG  ` `{ ` ` `  `// Function to print the largest n-digit even ` `// and odd numbers in octal number system ` `static` `void` `findNumbers(``int` `n) ` `{ ` ` `  `    ``// Append '7' (N - 1) times ` `    ``String ans = ``""``; ` `    ``for` `(``int` `i = 0; i < n - 1; i++) ` `        ``ans += ``'7'``; ` ` `  `    ``// Append '6' for an even number ` `    ``String even = ans + ``'6'``; ` ` `  `    ``// Append '7' for an odd number ` `    ``String odd = ans + ``'7'``; ` ` `  `    ``Console.WriteLine(``"Even : "` `+ even); ` `    ``Console.WriteLine(``"Odd : "` `+ odd); ` `} ` ` `  `// Driver code ` `public` `static` `void` `Main(String []args)  ` `{ ` `    ``int` `n = 4; ` ` `  `    ``findNumbers(n); ` `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

Output:

```Even : 7776
Odd : 7777
```

Time Complexity: O(n)

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