Lily's Homework | HackerRank

Whenever George asks Lily to hang out, she's busy doing homework. George wants to help her finish it faster, but he's in over his head! Can you help George understand Lily's homework so she can hang out with him?

Consider an array of distinct integers, . George can swap any two elements of the array any number of times. An array is beautiful if the sum of among is minimal.

Given the array , determine and return the minimum number of swaps that should be performed in order to make the array beautiful.

Example

One minimal array is . To get there, George performed the following swaps:

    Swap      Result
          [7, 15, 12, 3]
    3 7   [3, 15, 12, 7]
    7 15  [3, 7, 12, 15]

It took swaps to make the array beautiful. This is minimal among the choices of beautiful arrays possible.

Function Description

Complete the lilysHomework function in the editor below.

lilysHomework has the following parameter(s):

int arr[n]: an integer array

Returns

int: the minimum number of swaps required

Input Format

The first line contains a single integer, , the number of elements in . The second line contains space-separated integers, .

Constraints

Sample Input

STDIN       Function
-----       --------
4           arr[]size n = 4
2 5 3 1     arr = [2, 5, 3, 1]

Sample Output

Explanation

Define to be the beautiful reordering of . The sum of the absolute values of differences between its adjacent elements is minimal among all permutations and only two swaps ( with and then with ) were performed.