# Check whether bitwise AND of N numbers is Even or Odd

Given an array **arr[]** containing **N** numbers. The task is to check whether the bitwise-AND of the given **N** numbers is even or odd.

**Examples**:

Input:arr[] = { 2, 12, 20, 36, 38 }

Output:Even

Input:arr[] = { 3, 9, 17, 13, 15 }

Output:Odd

A **Simple Solution** is to first find the AND of the given N numbers, then check if this AND is even or odd.

A **Better Solution** is based on bit manipulation and Mathematical facts.

- Bitwise AND of any two even numbers is an even number.
- Bitwise AND of any two odd numbers is an odd number.
- Bitwise AND of an even and an odd number is an even number.

Based on the above facts, it can be deduced that if at least one even number is present in the array then the bitwise AND of whole array will be even otherwise odd.

Below is the implementation of the above approach:

## C++

`// C++ implementation of the approach ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` ` ` `// Function to check if the bitwise AND ` `// of the array elements is even or odd ` `void` `checkEvenOdd(` `int` `arr[], ` `int` `n) ` `{ ` ` ` `for` `(` `int` `i = 0; i < n; i++) { ` ` ` ` ` `// If at least an even element is present ` ` ` `// then the bitwise AND of the ` ` ` `// array elements will be even ` ` ` `if` `(arr[i] % 2 == 0) { ` ` ` ` ` `cout << ` `"Even"` `; ` ` ` `return` `; ` ` ` `} ` ` ` `} ` ` ` ` ` `cout << ` `"Odd"` `; ` `} ` ` ` `// Driver code ` `int` `main() ` `{ ` ` ` `int` `arr[] = { 2, 12, 20, 36, 38 }; ` ` ` `int` `n = ` `sizeof` `(arr) / ` `sizeof` `(arr[0]); ` ` ` ` ` `checkEvenOdd(arr, n); ` ` ` ` ` `return` `0; ` `} ` |

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## Java

`// Java implementation of the approach ` `import` `java.io.*; ` ` ` `class` `GFG ` `{ ` ` ` `// Function to check if the bitwise AND ` `// of the array elements is even or odd ` `static` `void` `checkEvenOdd(` `int` `[]arr, ` `int` `n) ` `{ ` ` ` `for` `(` `int` `i = ` `0` `; i < n; i++) ` ` ` `{ ` ` ` ` ` `// If at least an even element is present ` ` ` `// then the bitwise AND of the ` ` ` `// array elements will be even ` ` ` `if` `(arr[i] % ` `2` `== ` `0` `) ` ` ` `{ ` ` ` `System.out.print(` `"Even"` `); ` ` ` `return` `; ` ` ` `} ` ` ` `} ` ` ` `System.out.println(` `"Odd"` `); ` `} ` ` ` `// Driver code ` `public` `static` `void` `main (String[] args) ` `{ ` ` ` `int` `[]arr = { ` `2` `, ` `12` `, ` `20` `, ` `36` `, ` `38` `}; ` ` ` `int` `n = arr.length; ` ` ` ` ` `checkEvenOdd(arr, n); ` `} ` `} ` ` ` `// This code is contributed by @tushil ` |

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## Python3

`# Python3 implementation of the approach ` ` ` `# Function to check if the bitwise AND ` `# of the array elements is even or odd ` `def` `checkEvenOdd(arr, n) : ` ` ` ` ` `for` `i ` `in` `range` `(n) : ` ` ` ` ` `# If at least an even element is present ` ` ` `# then the bitwise AND of the ` ` ` `# array elements will be even ` ` ` `if` `(arr[i] ` `%` `2` `=` `=` `0` `) : ` ` ` ` ` `print` `(` `"Even"` `, end ` `=` `""); ` ` ` `return` `; ` ` ` ` ` `print` `(` `"Odd"` `, end ` `=` `""); ` ` ` `# Driver code ` `if` `__name__ ` `=` `=` `"__main__"` `: ` ` ` ` ` `arr ` `=` `[ ` `2` `, ` `12` `, ` `20` `, ` `36` `, ` `38` `]; ` ` ` `n ` `=` `len` `(arr); ` ` ` ` ` `checkEvenOdd(arr, n); ` ` ` `# This code is contributed by AnkitRai01 ` |

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## C#

`// C# implementation of the approach ` `using` `System; ` ` ` `class` `GFG ` `{ ` ` ` `// Function to check if the bitwise AND ` `// of the array elements is even or odd ` `static` `void` `checkEvenOdd(` `int` `[]arr, ` `int` `n) ` `{ ` ` ` `for` `(` `int` `i = 0; i < n; i++) ` ` ` `{ ` ` ` ` ` `// If at least an even element is present ` ` ` `// then the bitwise AND of the ` ` ` `// array elements will be even ` ` ` `if` `(arr[i] % 2 == 0) ` ` ` `{ ` ` ` `Console.Write (` `"Even"` `); ` ` ` `return` `; ` ` ` `} ` ` ` `} ` ` ` `Console.Write (` `"Odd"` `); ` `} ` ` ` `// Driver code ` `static` `public` `void` `Main () ` `{ ` ` ` `int` `[]arr = { 2, 12, 20, 36, 38 }; ` ` ` `int` `n = arr.Length; ` ` ` ` ` `checkEvenOdd(arr, n); ` `} ` `} ` ` ` `// This code is contributed by ajit.. ` |

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**Output:**

Even

**Time Complexity:** O(N)

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