# Sum of elements from an array having even parity

Given an array arr[], the task is to calculate the sum of the elements from the given array which has even parity i.e. the number of set bits is even using bitwise operator.

Examples:

Input: arr[] = {2, 4, 3, 5, 9}
Output: 17
Only 3(0011), 5(0101) and 9(1001) have even parity
So 3 + 5 + 9 = 17

Input: arr[] = {1, 5, 4, 16, 10}
Output: 15

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

Approach: Initialize a variable sum = 0 and traverse the array from 0 to n – 1 while counting the number of set bits in arr[i] using Brian Kernighan’s Algorithm. If the count is even then update sum = sum + arr[i]. Print the sum in the end.

Below is the implementation of the above approach:

## C++

 `// C++ program to find the sum of the elements ` `// from an array which have even parity ` `#include ` `using` `namespace` `std; ` ` `  `// Function that returns true if x has even parity ` `bool` `checkEvenParity(``int` `x) ` `{ ` `    ``// We basically count set bits  ` `    ``// https://www.geeksforgeeks.org/count-set-bits-in-an-integer/ ` `    ``int` `parity = 0; ` `    ``while` `(x != 0) { ` `        ``x = x & (x - 1); ` `        ``parity++; ` `    ``} ` ` `  `    ``if` `(parity % 2 == 0) ` `        ``return` `true``; ` `    ``else` `        ``return` `false``; ` `} ` ` `  `// Function to return the sum of the elements ` `// from an array which have even parity ` `long` `sumlist(``int` `a[], ``int` `n) ` `{ ` `    ``long` `sum = 0; ` ` `  `    ``for` `(``int` `i = 0; i < n; i++) { ` ` `  `        ``// If a[i] has even parity ` `        ``if` `(checkEvenParity(a[i])) ` `            ``sum += a[i]; ` `    ``} ` `    ``return` `sum; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 2, 4, 3, 5, 9 }; ` ` `  `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr); ` ` `  `    ``cout << sumlist(arr, n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to find the sum of the elements ` `// from an array which have even parity ` ` `  `import` `java.io.*; ` ` `  `class` `GFG { ` ` `  `// Function that returns true if x has even parity ` `static` `boolean` `checkEvenParity(``int` `x) ` `{ ` `    ``// We basically count set bits  ` `    ``// https://www.geeksforgeeks.org/count-set-bits-in-an-integer/ ` `    ``int` `parity = ``0``; ` `    ``while` `(x != ``0``) { ` `        ``x = x & (x - ``1``); ` `        ``parity++; ` `    ``} ` ` `  `    ``if` `(parity % ``2` `== ``0``) ` `        ``return` `true``; ` `    ``else` `        ``return` `false``; ` `} ` ` `  `// Function to return the sum of the elements ` `// from an array which have even parity ` `static` `long` `sumlist(``int` `a[], ``int` `n) ` `{ ` `    ``long` `sum = ``0``; ` ` `  `    ``for` `(``int` `i = ``0``; i < n; i++) { ` ` `  `        ``// If a[i] has even parity ` `        ``if` `(checkEvenParity(a[i])) ` `            ``sum += a[i]; ` `    ``} ` `    ``return` `sum; ` `} ` ` `  `// Driver code ` ` `  `    ``public` `static` `void` `main (String[] args) { ` `            ``int` `arr[] = { ``2``, ``4``, ``3``, ``5``, ``9` `}; ` ` `  `    ``int` `n =arr.length; ` ` `  `    ``System.out.println(sumlist(arr, n)); ` `    ``} ` `} ` `// This code is contributed by  inder_verma.. `

## Python3

 `# Python3 program to find the sum of the elements ` `# from an array which have even parity ` ` `  `# Function that returns true if x ` `# has even parity ` `def` `checkEvenParity(x): ` `     `  `    ``# We basically count set bits  ` `    ``# https://www.geeksforgeeks.org/count-set-bits-in-an-integer/ ` `    ``parity ``=` `0` `    ``while` `(x !``=` `0``): ` `        ``x ``=` `x & (x ``-` `1``) ` `        ``parity ``+``=` `1` ` `  `    ``if` `(parity ``%` `2` `=``=` `0``): ` `        ``return` `True` `    ``else``: ` `        ``return` `False` ` `  `# Function to return the sum of the elements ` `# from an array which have even parity ` `def` `sumlist(a, n): ` `    ``sum` `=` `0` `    ``for` `i ``in` `range``(n): ` `         `  `        ``# If a[i] has even parity ` `        ``if` `(checkEvenParity(a[i])): ` `            ``sum` `+``=` `a[i] ` `    ``return` `sum` ` `  `# Driver code ` `if` `__name__ ``=``=` `'__main__'``: ` `    ``arr ``=` `[ ``2``, ``4``, ``3``, ``5``, ``9` `] ` `    ``n ``=` `len``(arr) ` `    ``print``(sumlist(arr, n)) ` ` `  `# This code is contributed by 29AjayKumar. `

## C#

 `// C# program to find the sum of the elements  ` `// from an array which have even parity  ` ` `  `using` `System ; ` ` `  `class` `GFG {  ` ` `  `// Function that returns true if x has even parity  ` `static` `bool` `checkEvenParity(``int` `x)  ` `{  ` `    ``// We basically count set bits  ` `    ``// https://www.geeksforgeeks.org/count-set-bits-in-an-integer/  ` `    ``int` `parity = 0;  ` `    ``while` `(x != 0) {  ` `        ``x = x & (x - 1);  ` `        ``parity++;  ` `    ``}  ` ` `  `    ``if` `(parity % 2 == 0)  ` `        ``return` `true``;  ` `    ``else` `        ``return` `false``;  ` `}  ` ` `  `// Function to return the sum of the elements  ` `// from an array which have even parity  ` `static` `long` `sumlist(``int` `[]a, ``int` `n)  ` `{  ` `    ``long` `sum = 0;  ` ` `  `    ``for` `(``int` `i = 0; i < n; i++) {  ` ` `  `        ``// If a[i] has even parity  ` `        ``if` `(checkEvenParity(a[i]))  ` `            ``sum += a[i];  ` `    ``}  ` `    ``return` `sum;  ` `}  ` ` `  `// Driver code  ` ` `  `    ``public` `static` `void` `Main () {  ` `            ``int` `[]arr = { 2, 4, 3, 5, 9 };  ` ` `  `    ``int` `n =arr.Length;  ` ` `  `    ``Console.WriteLine(sumlist(arr, n));  ` `    ``}  ` `    ``// This code is contributed by Ryuga ` `}  `

## PHP

 ` `

Output:

```17
```

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