Given an array and a sorting algorithm, the sorting algorithm will do a selection swap. Find the number of swaps to sort the array.

For example the initical array is [5, 4, 1, 2], this is how the sorting algorithm works:
Swap index 0 with 1 to form the sorted array [4, 5, 1, 2].
Swap index 0 with 2 to form the sorted array [1, 5, 4, 2].
Swap index 1 with 2 to form the sorted array [1, 4, 5, 2].
Swap index 1 with 3 to form the sorted array [1, 2, 5, 4].
Swap index 2 with 3 to form the sorted array [1, 2, 4, 5].
Return 5.

Notice all elements of arr are unique

Example:
arr = [8, 2, 3]
return 2
explanation:
Swap a[0] and a[1]. The resulting array is [2, 8, 3].
Swap a[1] and a[2]. The resulting array is [2, 3, 8].
Return the number of swaps which is 2.