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# Rearrange all elements of array which are multiples of x in decreasing order

• Difficulty Level : Basic
• Last Updated : 04 May, 2021

Given an array of integers arr[] and an integer x, the task is to sort all the elements of the array which are multiples of x in decreasing order in their relative positions i.e. positions of the other elements must not be affected.

Examples:

Input: arr[] = {10, 5, 8, 2, 15}, x = 5
Output: 15 10 8 2 5
We rearrange all multiples of 5 (i.e. 10, 5 and 15) in decreasing order in their relative positions, keeping other elements same.

Input: arr[] = {100, 12, 25, 50, 5}, x = 5
Output: 100 12 50 25 5

Approach:

1. Traverse the array and check if the number is multiple of x. If it is, store it in a vector.
2. Then, sort the vector in decreasing order.
3. Again traverse the array and replace the elements which are multiples of 5 with the vector elements one by one.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function to sort all the``// multiples of x from the``// array in decreasing order``void` `sortMultiples(``int` `arr[], ``int` `n, ``int` `x)``{``    ``vector<``int``> v;` `    ``// Insert all multiples of x to a vector``    ``for` `(``int` `i = 0; i < n; i++)``        ``if` `(arr[i] % x == 0)``            ``v.push_back(arr[i]);` `    ``// Sort the vector in descending``    ``sort(v.begin(), v.end(), std::greater<``int``>());` `    ``int` `j = 0;` `    ``// update the array elements``    ``for` `(``int` `i = 0; i < n; i++) {``        ``if` `(arr[i] % x == 0)``            ``arr[i] = v[j++];``    ``}``}` `// Utility function to print the array``void` `printArray(``int` `arr[], ``int` `N)``{``    ``// Print the array``    ``for` `(``int` `i = 0; i < N; i++) {``        ``cout << arr[i] << ``" "``;``    ``}``}` `// Driver code``int` `main()``{``    ``int` `arr[] = { 125, 3, 15, 6, 100, 5 };``    ``int` `x = 5;``    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr[0]);` `    ``sortMultiples(arr, n, x);` `    ``printArray(arr, n);` `    ``return` `0;``}`

## Java

 `// Java implementation of the approach``import` `java.util.*;` `class` `GFG``{` `    ``// Function to sort all the``    ``// multiples of x from the``    ``// array in decreasing order``    ``static` `void` `sortMultiples(``int` `arr[], ``int` `n, ``int` `x)``    ``{``        ``Vector v = ``new` `Vector();` `        ``// Insert all multiples of x to a vector``        ``for` `(``int` `i = ``0``; i < n; i++)``        ``{``            ``if` `(arr[i] % x == ``0``)``            ``{``                ``v.add(arr[i]);``            ``}``        ``}` `        ``// Sort the vector in descending``        ``Collections.sort(v, Collections.reverseOrder());` `        ``int` `j = ``0``;` `        ``// update the array elements``        ``for` `(``int` `i = ``0``; i < n; i++)``        ``{``            ``if` `(arr[i] % x == ``0``)``            ``{``                ``arr[i] = v.get(j++);``            ``}``        ``}``    ``}` `    ``// Utility function to print the array``    ``static` `void` `printArray(``int` `arr[], ``int` `N)``    ``{``        ``// Print the array``        ``for` `(``int` `i = ``0``; i < N; i++)``        ``{``            ``System.out.print(arr[i] + ``" "``);``        ``}``    ``}` `    ``// Driver code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``int` `arr[] = {``125``, ``3``, ``15``, ``6``, ``100``, ``5``};``        ``int` `x = ``5``;``        ``int` `n = arr.length;` `        ``sortMultiples(arr, n, x);` `        ``printArray(arr, n);``    ``}``}` `// This code has been contributed by 29AjayKumar`

## Python3

 `# Python3 implementation of the approach` `# Function to sort all the``# multiples of x from the``# array in decreasing order``def` `sortMultiples(arr, n, x) :``    ``v ``=` `[]` `    ``# Insert all multiples of x``    ``# to a vector``    ``for` `i ``in` `range``(n) :``        ``if` `(arr[i] ``%` `x ``=``=` `0``) :``            ``v.append(arr[i])` `    ``# Sort the vector in descending``    ``v.sort(reverse ``=` `True``)``    ``j ``=` `0` `    ``# update the array elements``    ``for` `i ``in` `range``(n) :``        ``if` `(arr[i] ``%` `x ``=``=` `0``) :``            ``arr[i] ``=` `v[j]``            ``j ``+``=` `1``            ` `# Utility function to print the array``def` `printArray(arr, N) :` `    ``# Print the array``    ``for` `i ``in` `range``(N) :``        ``print``(arr[i], end ``=` `" "``)` `# Driver code``if` `__name__ ``=``=` `"__main__"` `:` `    ``arr``=` `[ ``125``, ``3``, ``15``, ``6``, ``100``, ``5` `]``    ``x ``=` `5``    ``n ``=` `len``(arr)``    ` `    ``sortMultiples(arr, n, x)` `    ``printArray(arr, n)` `# This code is contributed by Ryuga`

## C#

 `// C# implementation of the approach``using` `System;``using` `System.Collections.Generic;` `class` `GFG``{` `    ``// Function to sort all the``    ``// multiples of x from the``    ``// array in decreasing order``    ``static` `void` `sortMultiples(``int` `[]arr, ``int` `n, ``int` `x)``    ``{``        ``List<``int``> v = ``new` `List<``int``>();` `        ``// Insert all multiples of x to a vector``        ``for` `(``int` `i = 0; i < n; i++)``        ``{``            ``if` `(arr[i] % x == 0)``            ``{``                ``v.Add(arr[i]);``            ``}``        ``}` `        ``// Sort the vector in descending``        ``v.Sort();``        ``v.Reverse();` `        ``int` `j = 0;` `        ``// update the array elements``        ``for` `(``int` `i = 0; i < n; i++)``        ``{``            ``if` `(arr[i] % x == 0)``            ``{``                ``arr[i] = v[j++];``            ``}``        ``}``    ``}` `    ``// Utility function to print the array``    ``static` `void` `printArray(``int` `[]arr, ``int` `N)``    ``{``        ``// Print the array``        ``for` `(``int` `i = 0; i < N; i++)``        ``{``            ``Console.Write(arr[i] + ``" "``);``        ``}``    ``}` `    ``// Driver code``    ``public` `static` `void` `Main()``    ``{``        ``int` `[]arr = {125, 3, 15, 6, 100, 5};``        ``int` `x = 5;``        ``int` `n = arr.Length;` `        ``sortMultiples(arr, n, x);` `        ``printArray(arr, n);``    ``}``}` `/* This code contributed by PrinciRaj1992 */`

## PHP

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## Javascript

 ``
Output:
`125 3 100 6 15 5`

Time Complexity : O(n)

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