# Rearrange array such that even positioned are greater than odd

Given an array A of n elements, sort the array according to the following relations : , if i is even. , if i is odd.
Print the resultant array.

Examples :

```Input : A[] = {1, 2, 2, 1}
Output :  1 2 1 2
Explanation :
For 1st element, 1  1, i = 2 is even.
3rd element, 1  1, i = 4 is even.

Input : A[] = {1, 3, 2}
Output : 1 3 2
Explanation :
Here, the array is also sorted as per the conditions.
1  1 and 2 < 3.
```

Observe that array consists of [n/2] even positioned elements. If we assign largest [n/2] elements to the even positions and rest of the elements to the odd positions, our problem is solved. Because element at odd position will always be less than the element at even position as it is maximum element and vice versa. Sort the array and assign the first [n/2] elements at even positions.

Below is the implementation of above approach:

## C++

 `// C++ program to rearrange the elements  ` `// in array such that even positioned are  ` `// greater than odd positioned elements ` `#include ` `using` `namespace` `std; ` ` `  `void` `assign(``int` `a[], ``int` `n) ` `{ ` `    ``// Sort the array ` `    ``sort(a, a + n); ` ` `  `    ``int` `ans[n];  ` `    ``int` `p = 0, q = n - 1; ` `    ``for` `(``int` `i = 0; i < n; i++)  ` `    ``{ ` `        ``// Assign even indexes with maximum elements ` `        ``if` `((i + 1) % 2 == 0) ` `            ``ans[i] = a[q--]; ` ` `  `        ``// Assign odd indexes with remaining elements ` `        ``else` `            ``ans[i] = a[p++]; ` `    ``} ` ` `  `    ``// Print result ` `    ``for` `(``int` `i = 0; i < n; i++)  ` `        ``cout << ans[i] << ``" "``; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `A[] = { 1, 3, 2, 2, 5 }; ` `    ``int` `n = ``sizeof``(A) / ``sizeof``(A); ` `    ``assign(A, n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to rearrange the elements ` `// in array such that even positioned are ` `// greater than odd positioned elements ` `import` `java.io.*; ` `import` `java.util.*; ` ` `  `class` `GFG { ` ` `  `static` `void` `assign(``int` `a[], ``int` `n) { ` `     `  `    ``// Sort the array ` `    ``Arrays.sort(a); ` ` `  `    ``int` `ans[] = ``new` `int``[n]; ` `    ``int` `p = ``0``, q = n - ``1``; ` `    ``for` `(``int` `i = ``0``; i < n; i++) { ` `         `  `    ``// Assign even indexes with maximum elements ` `    ``if` `((i + ``1``) % ``2` `== ``0``) ` `        ``ans[i] = a[q--]; ` ` `  `    ``// Assign odd indexes with remaining elements ` `    ``else` `        ``ans[i] = a[p++]; ` `    ``} ` ` `  `    ``// Print result ` `    ``for` `(``int` `i = ``0``; i < n; i++) ` `    ``System.out.print(ans[i] + ``" "``); ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String args[]) { ` `    ``int` `A[] = {``1``, ``3``, ``2``, ``2``, ``5``}; ` `    ``int` `n = A.length; ` `    ``assign(A, n); ` `} ` `} ` ` `  `// This code is contributed by Nikita Tiwari. `

## Python3

 `# Python3 code to rearrange the ` `# elements in array such that ` `# even positioned are greater ` `# than odd positioned elements ` ` `  `def` `assign(a, n): ` `     `  `    ``# Sort the array ` `    ``a.sort() ` `     `  `    ``ans ``=` `[``0``] ``*` `n ` `    ``p ``=` `0` `    ``q ``=` `n ``-` `1` `    ``for` `i ``in` `range``(n): ` `         `  `        ``# Assign even indexes with ` `        ``# maximum elements ` `        ``if` `(i ``+` `1``) ``%` `2` `=``=` `0``: ` `            ``ans[i] ``=` `a[q] ` `            ``q ``=` `q ``-` `1` `         `  `        ``# Assign odd indexes with ` `        ``# remaining elements ` `        ``else``: ` `            ``ans[i] ``=` `a[p] ` `            ``p ``=` `p ``+` `1` `             `  `    ``# Print result ` `    ``for` `i ``in` `range``(n): ` `        ``print``(ans[i], end ``=` `" "``) ` ` `  `# Driver Code ` `A ``=` `[ ``1``, ``3``, ``2``, ``2``, ``5` `] ` `n ``=` `len``(A) ` `assign(A, n) ` ` `  `# This code is contributed by "Sharad_Bhardwaj". `

## C#

 `// C# program to rearrange the elements ` `// in array such that even positioned are ` `// greater than odd positioned elements ` `using` `System; ` ` `  `class` `GFG { ` ` `  `    ``static` `void` `assign(``int``[] a, ``int` `n) ` `    ``{ ` `        ``// Sort the array ` `        ``Array.Sort(a); ` ` `  `        ``int``[] ans = ``new` `int``[n]; ` `        ``int` `p = 0, q = n - 1; ` `        ``for` `(``int` `i = 0; i < n; i++) { ` ` `  `            ``// Assign even indexes with maximum elements ` `            ``if` `((i + 1) % 2 == 0) ` `                ``ans[i] = a[q--]; ` ` `  `            ``// Assign odd indexes with remaining elements ` `            ``else` `                ``ans[i] = a[p++]; ` `        ``} ` ` `  `        ``// Print result ` `        ``for` `(``int` `i = 0; i < n; i++) ` `            ``Console.Write(ans[i] + ``" "``); ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int``[] A = { 1, 3, 2, 2, 5 }; ` `        ``int` `n = A.Length; ` `        ``assign(A, n); ` `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## PHP

 ` `

Output:

```  1 5 2 3 2
```

## tags:

Arrays Sorting array-rearrange Arrays Sorting