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# Rearrange two given arrays to maximize sum of same indexed elements

• Last Updated : 18 May, 2021

Given two arrays A[] and B[] of size N, the task is to find the maximum possible sum of abs(A[i] – B[i]) by rearranging the array elements.

Examples:

Input: A[] = {1, 2, 3, 4, 5}, B[] = {1, 2, 3, 4, 5}
Output: 12
Explanation:
One of the possible rearrangements of A[] is {5, 4, 3, 2, 1}.
One of the possible rearrangements of B[] is {1, 2, 3, 4, 4}.
Therefore, the sum of all possible values of abs(A[i] – B[i]) = { abs(5 – 1) + abs(4 – 2) + abs(3 – 3) + abs(2 – 4) + abs(1 – 5) } = 12

Input: A[] = {1, 2, 2, 4, 5}, B[] = {5, 5, 5, 6, 6}
Output: 13
Explanation:
One of the possible rearrangements of A[] is {5, 4, 2, 2, 1}.
One of the possible rearrangements of B[] is {5, 5, 5, 6, 6}.
Therefore, the sum of all possible values of abs(A[i] – B[i]) = { abs(5 – 5) + abs(4 – 5) + abs(2 – 5) + abs(2 – 6) + abs(1 – 6) } = 13

Approach: Follow the steps below to solve the problem:

Below is the implementation of the above approach:

## C++

 `// C++ program to implement``// the above approach``#include ``using` `namespace` `std;` `// Function to find the maximum possible sum``// by rearranging the given array elements``int` `MaxRearrngeSum(``int` `A[], ``int` `B[], ``int` `N)``{``    ` `    ``// Sort the array A[]``    ``// in ascending order``    ``sort(A, A + N);``    ` `    ` `    ``// Sort the array B[]``    ``// in descending order``    ``sort(B, B + N,``            ``greater<``int``>());``    ` `    ` `    ``// Stores maximum possible sum``    ``// by rearranging array elements        ``    ``int` `maxSum = 0;``    ` `    ` `    ``// Traverse both the arrays``    ``for` `(``int` `i = 0; i < N; i++) {``        ` `        ` `        ``// Update maxSum``        ``maxSum += ``abs``(A[i] - B[i]);``    ``}``    ` `    ``return` `maxSum;` `}` `// Driver Code``int` `main()` `{` `    ``int` `A[] = { 1, 2, 2, 4, 5 };``    ``int` `B[] = { 5, 5, 5, 6, 6 };` `    ``int` `N = ``sizeof``(A) / ``sizeof``(A);` `    ``cout<< MaxRearrngeSum(A, B, N);` `    ``return` `0;``}`

## Java

 `// Java program to implement``// the above approach``import` `java.lang.Math;``import` `java.util.Arrays;``import` `java.util.Collections;` `class` `GFG{``    ` `// Function to find the maximum possible sum``// by rearranging the given array elements``static` `int` `MaxRearrngeSum(Integer A[],``                          ``Integer B[],``                          ``int` `N)``{``    ` `    ``// Sort the array A[]``    ``// in ascending order``    ``Arrays.sort(A);``    ` `    ``// Sort the array B[]``    ``// in descending order``    ``Arrays.sort(B, Collections.reverseOrder());``    ` `    ``// Stores maximum possible sum``    ``// by rearranging array elements         ``    ``int` `maxSum = ``0``;``    ` `    ``// Traverse both the arrays``    ``for``(``int` `i = ``0``; i < N; i++)``    ``{``        ``// Update maxSum``        ``maxSum += Math.abs(A[i] - B[i]);``    ``}``    ``return` `maxSum;``}``  ` `// Driver code``public` `static` `void` `main (String[] args)``{``    ``Integer A[] = { ``1``, ``2``, ``2``, ``4``, ``5` `};``    ``Integer B[] = { ``5``, ``5``, ``5``, ``6``, ``6` `};` `    ``int` `N = A.length;``  ` `    ``System.out.println(MaxRearrngeSum(A, B, N));``}``}` `// This code is contributed by ujjwalgoel1103`

## Python3

 `# Python3 program to implement``# the above approach` `# Function to find the maximum possible sum``# by rearranging the given array elements``def` `MaxRearrngeSum(A, B, N):``    ` `    ``# Sort the array A[]``    ``# in ascending order``    ``A.sort()` `    ``# Sort the array B[]``    ``# in descending order``    ``B.sort(reverse ``=` `True``)` `    ``# Stores maximum possible sum``    ``# by rearranging array elements``    ``maxSum ``=` `0` `    ``# Traverse both the arrays``    ``for` `i ``in` `range``(N):` `        ``# Update maxSum``        ``maxSum ``+``=` `abs``(A[i] ``-` `B[i])` `    ``return` `maxSum` `# Driver Code``if` `__name__ ``=``=` `"__main__"``:` `    ``A ``=` `[ ``1``, ``2``, ``2``, ``4``, ``5` `]``    ``B ``=` `[ ``5``, ``5``, ``5``, ``6``, ``6` `]` `    ``N ``=` `len``(A)` `    ``print``(MaxRearrngeSum(A, B, N))` `# This code is contributed by chitranayal`

## C#

 `// Java program to implement``// the above approach``using` `System;` `class` `GFG{``    ` `// Function to find the maximum possible sum``// by rearranging the given array elements``static` `int` `MaxRearrngeSum(``int` `[]A, ``int` `[]B, ``int` `N)``{``    ` `    ``// Sort the array A[]``    ``// in ascending order``    ``Array.Sort(A);``    ` `    ``// Sort the array B[]``    ``// in descending order``    ``Array.Sort(B);``    ``Array.Reverse(B);``    ` `    ``// Stores maximum possible sum``    ``// by rearranging array elements         ``    ``int` `maxSum = 0;``    ` `    ``// Traverse both the arrays``    ``for``(``int` `i = 0; i < N; i++)``    ``{``        ` `        ``// Update maxSum``        ``maxSum += Math.Abs(A[i] - B[i]);``    ``}``    ``return` `maxSum;``}``  ` `// Driver code``public` `static` `void` `Main()``{``    ``int` `[]A = { 1, 2, 2, 4, 5 };``    ``int` `[]B = { 5, 5, 5, 6, 6 };` `    ``int` `N = A.Length;``  ` `    ``Console.WriteLine(MaxRearrngeSum(A, B, N));``}``}` `// This code is contributed by ipg2016107`

## Javascript

 ``
Output:
`13`

Time Complexity: O(N * Log N)
Auxiliary Space: O(1)

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