HACKER RANK - ARRAYS - MINIMUM SWAPS

You are given an unordered array consisting of consecutive integers  [1, 2, 3, ..., n] without any duplicates. You are allowed to swap any two elements. Find the minimum number of swaps required to sort the array in ascending order.

Example

Perform the following steps:

i   arr                         swap (indices)
0   [7, 1, 3, 2, 4, 5, 6]   swap (0,3)
1   [2, 1, 3, 7, 4, 5, 6]   swap (0,1)
2   [1, 2, 3, 7, 4, 5, 6]   swap (3,4)
3   [1, 2, 3, 4, 7, 5, 6]   swap (4,5)
4   [1, 2, 3, 4, 5, 7, 6]   swap (5,6)
5   [1, 2, 3, 4, 5, 6, 7]

It took  swaps to sort the array.

Function Description

Complete the function minimumSwaps in the editor below.

minimumSwaps has the following parameter(s):

• int arr[n]: an unordered array of integers

Returns

• int: the minimum number of swaps to sort the array

Input Format

The first line contains an integer, , the size of .
The second line contains  space-separated integers .

Constraints

Sample Input 0

4
4 3 1 2

Sample Output 0

3

Explanation 0

Given array 
After swapping  we get 
After swapping  we get 
After swapping  we get 
So, we need a minimum of  swaps to sort the array in ascending order.

Sample Input 1

5
2 3 4 1 5

Sample Output 1

3

Explanation 1

Given array 
After swapping  we get 
After swapping  we get 
After swapping  we get 
So, we need a minimum of  swaps to sort the array in ascending order.

SOLUTION:

//python

def minimumSwaps(arr):

    a=dict(enumerate(arr,1))

    b={v:k for k,v in a.items()}

    count=0

    for i in a:

        x=a[i]

        if x!=i:

            y=b[i]

            a[y]=x

            b[x]=y

            count+=1

    return count