# Count of Smaller Numbers after Self | Number of Swaps to Sort | Algorithm Swap

You are given an integer array nums and you have to return a new counts array. The counts array has the property where `counts[i]`

is the number of smaller elements to the right of `nums[i]`

.

Input:

` [5,2,6,1]`

Output:

` [2,1,1,0]`

Explanation:

For the number 5, there are 2 numbers smaller than it after it. (2 and 1)

For the number 2, there is 1 number smaller than it after it. (1)

For the number 6, there is also 1 number smaller than it after it. (1)

For the number 1, there are no numbers smaller than it after it.

Hence, we have `[2, 1, 1, 0]`

.

## Number of swaps to sort

Another way to phrase the question is:

If we sort the array by finding the smallest pair `i, j`

where `i < j`

and `a[i] > a[j]`

how many swaps are needed?

To answer that question we just have to sum up the numbers in the above output array: `2 + 1 + 1 = 5`

swaps.

### Try it yourself

## Title

### Script

Lorem Ipsum is simply dummy text of the printing and typesetting industry. `Lorem`

`Ipsum`

has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.

Contrary to popular belief, `Lorem`

`Ipsum`

is not simply random text.

```
>>> a = [1, 2, 3]
>>> a[-1]
3
```