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# Minimum increment/decrement operations required to make Median as X

• Difficulty Level : Medium
• Last Updated : 23 Apr, 2021

Given an array A[] of n odd integers and an integer X. Calculate the minimum number of operations required to make the median of the array equal to X, where, in one operation we can either increase or decrease any single element by one.

Examples:

Input: A[] = {6, 5, 8}, X = 8
Output:
Explanation:
Here 6 can be increased twice. The array will become 8, 5, 8, which becomes 5, 8, 8 after sorting, hence the median is equal to 8.

Input: A[] = {1, 4, 7, 12, 3, 5, 9}, X = 5
Output:
Explanation:
After sorting 5 is in middle position hence 0 steps are required.

Approach: The idea for changing the median of the array will be to sort the given array. Then after sorting, the best possible candidate for making the median is the middle element because it will be better to reduce the numbers before the middle element as they are smaller and increase the numbers after the middle element as they are larger.

Below is the implementation of the above approach:

## C++

 `// C++ implementation to determine the ` `// Minimum numbers of steps to make ` `// median of an array equal X `   `#include ` `using` `namespace` `std; `   `// Function to count minimum ` `// required operations to ` `// make median X ` `int` `count(vector<``int``> a, ``int` `X) ` `{ ` `    ``// Sorting the array a[] ` `    ``sort(a.begin(), a.end()); ` `    ``int` `ans = 0; `   `    ``// Calculate the size of array ` `    ``int` `n = a.size(); `   `    ``// Iterate over the array ` `    ``for` `(``int` `i = 0; i < n; i++) { ` `        ``// For all elements ` `        ``// less than median ` `        ``if` `(i < n / 2) ` `            ``ans += max(0, a[i] - X); `   `        ``// For element equal ` `        ``// to median ` `        ``else` `if` `(i == n / 2) ` `            ``ans += ``abs``(X - a[i]); `   `        ``// For all elements ` `        ``// greater than median ` `        ``else` `            ``ans += max(0, X - a[i]); ` `    ``} `   `    ``// Return the answer ` `    ``return` `ans; ` `} `   `// Driver code ` `int` `main() ` `{ ` `    ``vector<``int``> a = { 6, 5, 8 }; ` `    ``int` `X = 8; ` `    ``cout << count(a, X) << ``"\n"``; ` `    ``return` `0; ` `} `

## Java

 `// Java implementation to determine the` `// Minimum numbers of steps to make` `// median of an array equal X` `import` `java.util.*;`   `class` `GFG{`   `// Function to count minimum` `// required operations to` `// make median X` `static` `int` `count(``int``[] a, ``int` `X)` `{` `    `  `    ``// Sorting the array a[]` `    ``Arrays.sort(a);` `    ``int` `ans = ``0``;`   `    ``// Calculate the size of array` `    ``int` `n = a.length;`   `    ``// Iterate over the array` `    ``for``(``int` `i = ``0``; i < n; i++)` `    ``{` `       `  `       ``// For all elements` `       ``// less than median` `       ``if` `(i < n / ``2``)` `           ``ans += Math.max(``0``, a[i] - X);` `       `  `       ``// For element equal` `       ``// to median` `       ``else` `if` `(i == n / ``2``)` `           ``ans += Math.abs(X - a[i]);` `      `  `       ``// For all elements` `       ``// greater than median` `       ``else` `           ``ans += Math.max(``0``, X - a[i]);` `    ``}` `    `  `    ``// Return the answer` `    ``return` `ans;` `}`   `// Driver code` `public` `static` `void` `main(String[] args)` `{` `    ``int` `[]a = { ``6``, ``5``, ``8` `};` `    ``int` `X = ``8``;` `    `  `    ``System.out.print(count(a, X) + ``"\n"``);` `}` `}`   `// This code is contributed by Amit Katiyar`

## Python3

 `# Python3 implementation to determine the ` `# Minimum numbers of steps to make ` `# median of an array equal X `   `# Function to count minimum ` `# required operations to ` `# make median X ` `def` `count(a, X): `   `    ``# Sorting the array a[] ` `    ``a.sort()` `    ``ans ``=` `0`   `    ``# Calculate the size of array ` `    ``n ``=` `len``(a)`   `    ``# Iterate over the array ` `    ``for` `i ``in` `range``(n):` `        `  `        ``# For all elements ` `        ``# less than median ` `        ``if` `(i < n ``/``/` `2``): ` `            ``ans ``+``=` `max``(``0``, a[i] ``-` `X)`   `        ``# For element equal ` `        ``# to median ` `        ``elif` `(i ``=``=` `n ``/``/` `2``): ` `            ``ans ``+``=` `abs``(X ``-` `a[i]) `   `        ``# For all elements ` `        ``# greater than median ` `        ``else``:` `            ``ans ``+``=` `max``(``0``, X ``-` `a[i]); `   `    ``# Return the answer ` `    ``return` `ans`   `# Driver code` `a ``=` `[ ``6``, ``5``, ``8` `] ` `X ``=` `8`   `print``(count(a, X)) `   `# This code is contributed by divyeshrabadiya07`

## C#

 `// C# implementation to determine the` `// Minimum numbers of steps to make` `// median of an array equal X` `using` `System;`   `class` `GFG{`   `// Function to count minimum` `// required operations to` `// make median X` `static` `int` `count(``int``[] a, ``int` `X)` `{` `    `  `    ``// Sorting the array []a` `    ``Array.Sort(a);` `    ``int` `ans = 0;`   `    ``// Calculate the size of array` `    ``int` `n = a.Length;`   `    ``// Iterate over the array` `    ``for``(``int` `i = 0; i < n; i++)` `    ``{` `       `  `       ``// For all elements` `       ``// less than median` `       ``if` `(i < n / 2)` `           ``ans += Math.Max(0, a[i] - X);` `           `  `       ``// For element equal` `       ``// to median` `       ``else` `if` `(i == n / 2)` `           ``ans += Math.Abs(X - a[i]);` `       `  `       ``// For all elements` `       ``// greater than median` `       ``else` `           ``ans += Math.Max(0, X - a[i]);` `    ``}` `    `  `    ``// Return the answer` `    ``return` `ans;` `}`   `// Driver code` `public` `static` `void` `Main(String[] args)` `{` `    ``int` `[]a = { 6, 5, 8 };` `    ``int` `X = 8;` `    `  `    ``Console.Write(count(a, X) + ``"\n"``);` `}` `}`   `// This code is contributed by Amit Katiyar`

## Javascript

 ``

Output:

`2`

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

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