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 <bits/stdc++.h> 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[0]); 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
<?php // PHP implementation to // find sum of even numbers // at even indices // Function to calculate sum // of even numbers at even indices function sum_even_and_even_index($arr, $n) { $i = 0; $sum = 0; // calculating sum of even // number at even index for ($i = 0; $i < $n; $i=$i+2) { if ($arr[$i] % 2 == 0) { $sum += $arr[$i]; } } // required sum return $sum; } // Driver Code { $arr = array(5, 6, 12, 1, 18, 8); $n = sizeof($arr) / sizeof($arr[0]); echo "Sum of even numbers at ". "even indices is ", sum_even_and_even_index($arr, $n); return 0; } // This code is contributed by nitin mittal. ?> |
Output:
Sum of even numbers at even indices is 30
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