# Maximum OR value of a pair in an array

Given an array arr[] of N positive elements. The task is to find the maximum bitwise OR value of a pair from the given array.

Examples:

Input: arr[] = {4, 8, 12, 16}
Output: 28
(12, 16) is the pair with the maximum bitwise OR.
12 | 16 = 28

Input: arr[] = {4, 8, 16, 2}
Output: 24

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

Approach: Iterate over all the possible pairs and calculate the OR value of these pairs. Finally, print the maximum of all the values.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to return the maximum bitwise OR ` `// for any pair of the given array ` `int` `maxOR(``int` `arr[], ``int` `n) ` `{ ` ` `  `    ``// To store the maximum OR value ` `    ``int` `maxVal = 0; ` ` `  `    ``// For every possible pair ` `    ``for` `(``int` `i = 0; i < n - 1; i++) ` `        ``for` `(``int` `j = i + 1; j < n; j++) { ` ` `  `            ``// Update the maximum OR value ` `            ``maxVal = max(maxVal, arr[i] | arr[j]); ` `        ``} ` ` `  `    ``return` `maxVal; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 4, 8, 12, 16 }; ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr); ` ` `  `    ``cout << maxOR(arr, n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java implementation of the approach  ` `class` `GFG  ` `{ ` `     `  `    ``// Function to return the maximum bitwise OR  ` `    ``// for any pair of the given array  ` `    ``static` `int` `maxOR(``int` `arr[], ``int` `n)  ` `    ``{  ` `     `  `        ``// To store the maximum OR value  ` `        ``int` `maxVal = ``0``;  ` `     `  `        ``// For every possible pair  ` `        ``for` `(``int` `i = ``0``; i < n - ``1``; i++)  ` `            ``for` `(``int` `j = i + ``1``; j < n; j++) ` `            ``{  ` `     `  `                ``// Update the maximum OR value  ` `                ``maxVal = Math.max(maxVal, arr[i] | arr[j]);  ` `            ``}  ` `     `  `        ``return` `maxVal;  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `main (String[] args)  ` `    ``{  ` `        ``int` `arr[] = { ``4``, ``8``, ``12``, ``16` `};  ` `        ``int` `n = arr.length;  ` `     `  `        ``System.out.println(maxOR(arr, n));  ` `    ``} ` `} ` ` `  `// This code is contributed by AnkitRai01 `

## Python3

 `# Python3 implementation of the approach ` ` `  `# Function to return the maximum bitwise OR ` `# for any pair of the given array ` `def` `maxOR(arr, n): ` `     `  `    ``# To store the maximum OR value ` `    ``maxVal ``=` `0``; ` ` `  `    ``# For every possible pair ` `    ``for` `i ``in` `range``(n ``-` `1``): ` `        ``for` `j ``in` `range``(i ``+` `1``, n): ` `             `  `            ``# Update the maximum OR value ` `            ``maxVal ``=` `max``(maxVal, arr[i] | arr[j]); ` ` `  `    ``return` `maxVal; ` ` `  `# Driver code ` `if` `__name__ ``=``=` `'__main__'``: ` `    ``arr ``=` `[``4``, ``8``, ``12``, ``16``]; ` `    ``n ``=` `len``(arr); ` ` `  `    ``print``(maxOR(arr, n)); ` ` `  `# This code is contributed by 29AjayKumar `

## C#

 `// C# implementation of the approach  ` `using` `System; ` ` `  `class` `GFG ` `{ ` `         `  `// Function to return the maximum bitwise OR  ` `// for any pair of the given array  ` `static` `int` `maxOR(``int` `[]arr, ``int` `n)  ` `{  ` ` `  `    ``// To store the maximum OR value  ` `    ``int` `maxVal = 0;  ` ` `  `    ``// For every possible pair  ` `    ``for` `(``int` `i = 0; i < n - 1; i++)  ` `        ``for` `(``int` `j = i + 1; j < n; j++) ` `        ``{  ` ` `  `            ``// Update the maximum OR value  ` `            ``maxVal = Math.Max(maxVal, arr[i] | arr[j]);  ` `        ``}  ` ` `  `    ``return` `maxVal;  ` `}  ` ` `  `// Driver code ` `static` `public` `void` `Main () ` `{ ` `    ``int` `[]arr = { 4, 8, 12, 16 };  ` `    ``int` `n = arr.Length;  ` ` `  `    ``Console.Write(maxOR(arr, n));  ` `} ` `} ` ` `  `// This code is contributed by ajit. `

Output:

```28
```

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