# 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
```

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

 `// 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++) { ` `     `  `        ``if` `((i % 2 == 0) &&  ` `            ``(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[0]); ` `    ``cout << ``"Sum of even numbers at even indices is "` `         ``<< sum_even_and_even_index(arr, n); ` `     `  `    ``return` `0; ` `} `

 `// 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++) { ` `         `  `            ``if` `((i % ``2` `== ``0``) &&  ` `                ``(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. `

 `# 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): ` `        ``if` `((i ``%` `2` `=``=` `0``) ``and` `              ``(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# 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++) { ` `         `  `            ``if` `((i % 2 == 0) &&  ` `                ``(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. `

 ` `

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

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Improved By : nitin mittal, Sam007

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