# Sum of even numbers at even position

Given an array of size n. The problem is to find the sum of numbers which are even and are at even index.

Examples:

```Input :  arr[] = {5, 6, 12, 1, 18, 8}
Output : 30
Explanation: Here, n = 6
Now here are index and numbers as: index->arr[index]
0->5, 1->6, 2->12, 3->1, 4->18, 5->8
so, number which are even and are at even indices
are: 2->12, 4->18
sum = 12+18 = 30

Input  : arr[] = {3, 20, 17, 9, 2, 10,
18, 13, 6, 18}
Output : 26
Explanation: Here, n = 10
Now here are index and numbers as: index->arr[index]
0->3, 1->20, 2->17, 3->9, 4->2, 5->10,
6->18, 7->13, 8->6, 9->18
So, number which are even and are at even indices are:
4->2, 6->18, 8->6
sum = 2+18+6 = 26
```

## C++

 `// C++ implementation to  ` `// find sum of even numbers ` `// at even indices ` `#include ` `using` `namespace` `std; ` ` `  `// Function to calculate sum  ` `// of even numbers at even indices ` `int` `sum_even_and_even_index( ` `                ``int` `arr[], ``int` `n) { ` ` `  `    ``int` `i = 0, sum = 0; ` `     `  `    ``// calculating sum of even ` `    ``// number at even index ` `    ``for` `(i = 0; i < n; i+=2) { ` `     `  `        ``if` `(arr[i] % 2 == 0) { ` `             `  `            ``sum += arr[i]; ` `        ``} ` `    ``} ` `     `  `    ``// required sum ` `    ``return` `sum; ` `} ` ` `  `// Driver program to test above ` `int` `main() { ` `    ``int` `arr[] = {5, 6, 12, 1, 18, 8}; ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr); ` `    ``cout << ``"Sum of even numbers at even indices is "` `         ``<< sum_even_and_even_index(arr, n); ` `     `  `    ``return` `0; ` `} `

## Java

 `// Java implementation to find sum of  ` `// even numbers at even indices ` ` `  `import` `java.io.*; ` ` `  `class` `GFG { ` `     `  `    ``// Function to calculate sum  ` `    ``// of even numbers at even indices ` `    ``static` `int` `sum_even_and_even_index( ` `                       ``int` `arr[], ``int` `n) ` `    ``{ ` `     `  `        ``int` `i = ``0``, sum = ``0``; ` `         `  `        ``// calculating sum of even ` `        ``// number at even index ` `        ``for` `(i = ``0``; i < n; i+=``2``) { ` `         `  `            ``if` `(arr[i] % ``2` `== ``0``) { ` `                ``sum += arr[i]; ` `            ``} ` `        ``} ` `         `  `        ``// required sum ` `        ``return` `sum; ` `    ``} ` ` `  `    ``// Driver program to test above ` `    ``public` `static` `void` `main (String[] args) { ` `         `  `        ``int` `arr[] = {``5``, ``6``, ``12``, ``1``, ``18``, ``8``}; ` `        ``int` `n = arr.length; ` `        ``System.out.println(``"Sum of even numbers"` `                      ``+ ``" at even indices is "` `+ ` `             ``+ sum_even_and_even_index(arr, n)); ` `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## Python3

 `# python 3 implementation to  ` `# find sum of even numbers ` `# at even indices ` ` `  `# Function to calculate sum  ` `# of even numbers at even indices ` `def` `sum_even_and_even_index(arr,n): ` `     `  `    ``i ``=` `0` `    ``sum` `=` `0` `     `  `# calculating sum of even ` `# number at even index ` `    ``for` `i ``in` `range``(``0``,n,``2``): ` `        ``if` `(arr[i] ``%` `2` `=``=` `0``) : ` `            ``sum` `+``=` `arr[i] ` `         `  `    ``# required sum ` `    ``return` `sum` ` `  ` `  `# Driver program to test above ` `arr ``=` `[``5``, ``6``, ``12``, ``1``, ``18``, ``8``] ` `n ``=` `len``(arr) ` `print``(``"Sum of even numbers at "``, ` `             ``"even indices is "``,  ` `   ``sum_even_and_even_index(arr, n)) ` `     `  `# This code is contributed by Sam007 `

## C#

 `// C# implementation to find sum of  ` `// even numbers at even indices ` ` `  `using` `System; ` ` `  `class` `GFG { ` `     `  `    ``// Function to calculate sum  ` `    ``// of even numbers at even indices ` `    ``static` `int` `sum_even_and_even_index( ` `                    ``int` `[]arr, ``int` `n) ` `    ``{ ` `     `  `        ``int` `i = 0, sum = 0; ` `         `  `        ``// calculating sum of even ` `        ``// number at even index ` `        ``for` `(i = 0; i < n; i+=2) { ` `         `  `            ``if` `(arr[i] % 2 == 0) { ` `                 `  `                ``sum += arr[i]; ` `            ``} ` `        ``} ` `         `  `        ``// required sum ` `        ``return` `sum; ` `    ``} ` ` `  `    ``// Driver program to test above ` `    ``public` `static` `void` `Main () { ` `         `  `        ``int` `[]arr = {5, 6, 12, 1, 18, 8}; ` `        ``int` `n = arr.Length; ` `        ``Console.WriteLine(``"Sum of even numbers"` `                    ``+ ``" at even indices is "` `+ ` `            ``+ sum_even_and_even_index(arr, n)); ` `    ``} ` `} ` ` `  `//This code is contributed by vt_m. `

## PHP

 ` `

Output:

``` Sum of even numbers at even indices is 30
```

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