Prerequisite – Array Basics

Given an array, write a program to find the sum of values of even and odd index positions separately.

Examples:

Input :arr = {1, 2, 3, 4, 5, 6}Output :Even index positions sum 9 Odd index positions sum 12Explanation:Here, n = 6 so there will be 3 even index positions and 3 odd index positions in an array Even = 1 + 3 + 5 = 9 Odd = 2 + 4 + 6 = 12Input :arr = {10, 20, 30, 40, 50, 60, 70}Output :Even index positions sum 160 Odd index positions sum 170Explanation:Here, n = 7 so there will be 3 odd index positions and 4 even index positions in an array Even = 10 + 30 + 50 + 70 = 160 Odd = 20 + 40 + 60 = 120

## C/C++

`// CPP program to find out ` `// Sum of elements at even and ` `// odd index positions separately ` `#include <iostream> ` ` ` `using` `namespace` `std; ` ` ` `// Function to calculate sum ` `void` `EvenOddSum(` `int` `arr[], ` `int` `n) ` `{ ` ` ` `int` `even = 0; ` ` ` `int` `odd = 0; ` ` ` `for` `(` `int` `i = 0; i < n; i++) { ` ` ` `// Loop to find even, odd sum ` ` ` `if` `(i % 2 == 0) ` ` ` `even += arr[i]; ` ` ` `else` ` ` `odd += arr[i]; ` ` ` `} ` ` ` ` ` `cout << ` `"Even index positions sum "` `<< even; ` ` ` `cout << ` `"\nOdd index positions sum "` `<< odd; ` `} ` ` ` `// Driver function ` `int` `main() ` `{ ` ` ` `int` `arr[] = { 1, 2, 3, 4, 5, 6 }; ` ` ` `int` `n = ` `sizeof` `(arr) / ` `sizeof` `(arr[0]); ` ` ` ` ` `EvenOddSum(arr, n); ` ` ` ` ` `return` `0; ` `} ` |

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## Java

`// Java program to find out ` `// Sum of elements at even and ` `// odd index positions separately ` `import` `java.io.*; ` ` ` `class` `EvenOddSum { ` ` ` `public` `static` `void` `main(String args[]) ` ` ` `{ ` ` ` `int` `arr[] = { ` `1` `, ` `2` `, ` `3` `, ` `4` `, ` `5` `, ` `6` `}; ` ` ` `int` `even = ` `0` `, odd = ` `0` `; ` ` ` ` ` `// Loop to find even, odd sum ` ` ` `for` `(` `int` `i = ` `0` `; i < arr.length; i++) { ` ` ` `if` `(i % ` `2` `== ` `0` `) ` ` ` `even += arr[i]; ` ` ` `else` ` ` `odd += arr[i]; ` ` ` `} ` ` ` ` ` `System.out.println(` `"Even index positions sum: "` `+ even); ` ` ` `System.out.println(` `"Odd index positions sum: "` `+ odd); ` ` ` `} ` `} ` |

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## Python

`# Python program to find out ` `# Sum of elements at even and ` `# odd index positions separately ` ` ` `# Function to calculate Sum ` `def` `EvenOddSum(a, n): ` ` ` `even ` `=` `0` ` ` `odd ` `=` `0` ` ` `for` `i ` `in` `range` `(n): ` ` ` ` ` `# Loop to find evem, odd Sum ` ` ` `if` `i ` `%` `2` `=` `=` `0` `: ` ` ` `even ` `+` `=` `a[i] ` ` ` `else` `: ` ` ` `odd ` `+` `=` `a[i] ` ` ` ` ` `print` `"Even index positions sum "` `, even ` ` ` `print` `"nOdd index positions sum "` `, odd ` ` ` `# Driver Function ` ` ` `arr ` `=` `[` `1` `, ` `2` `, ` `3` `, ` `4` `, ` `5` `, ` `6` `] ` `n ` `=` `len` `(arr) ` ` ` `EvenOddSum(arr, n) ` ` ` `# This code is contributed by Sachin Bisht ` |

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## C#

`// C# program to find out ` `// Sum of elements at even and ` `// odd index positions separately ` `using` `System; ` ` ` `public` `class` `GFG { ` ` ` ` ` `public` `static` `void` `Main() ` ` ` `{ ` ` ` `int` `[] arr = { 1, 2, 3, 4, 5, 6 }; ` ` ` `int` `even = 0, odd = 0; ` ` ` ` ` `// Loop to find even, odd sum ` ` ` `for` `(` `int` `i = 0; i < arr.Length; i++) ` ` ` `{ ` ` ` `if` `(i % 2 == 0) ` ` ` `even += arr[i]; ` ` ` `else` ` ` `odd += arr[i]; ` ` ` `} ` ` ` ` ` `Console.WriteLine(` `"Even index positions"` ` ` `+ ` `" sum: "` `+ even); ` ` ` ` ` `Console.WriteLine(` `"Odd index positions "` ` ` `+ ` `"sum: "` `+ odd); ` ` ` `} ` `} ` ` ` `// This code is contributed by Sam007. ` |

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## PHP

`<?php ` `// PHP program to find out ` `// Sum of elements at even and ` `// odd index positions separately ` ` ` `// Function to calculate sum ` `function` `EvenOddSum(` `$arr` `, ` `$n` `) ` `{ ` ` ` `$even` `= 0; ` ` ` `$odd` `= 0; ` ` ` `for` `(` `$i` `= 0; ` `$i` `< ` `$n` `; ` `$i` `++) ` ` ` `{ ` ` ` ` ` `// Loop to find even, odd sum ` ` ` `if` `(` `$i` `% 2 == 0) ` ` ` `$even` `+= ` `$arr` `[` `$i` `]; ` ` ` `else` ` ` `$odd` `+= ` `$arr` `[` `$i` `]; ` ` ` `} ` ` ` ` ` `echo` `(` `"Even index positions sum "` `. ` `$even` `); ` ` ` `echo` `(` `"\nOdd index positions sum "` `. ` `$odd` `); ` `} ` ` ` `// Driver Code ` `$arr` `= ` `array` `( 1, 2, 3, 4, 5, 6 ); ` `$n` `= sizeof(` `$arr` `); ` ` ` `EvenOddSum(` `$arr` `, ` `$n` `); ` ` ` `// This code is contributed by Ajit. ` `?> ` |

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Output:

Even index positions sum 9 Odd index positions sum 12

This article is contributed by **Rishabh Jain**. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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