Quick Sort - First Element As Pivot
Usually, a random pivot is selected and moved to the first location.
After swapping -13 and 22, your pointers should be on 7 and 34.

7 and 34 are correctly placed.
Also 7 and 34 are adjacent, so time has come to put the pivot in its correct place.

array looks like this

15, -7, -13, 7, 34, 22, 19

So now you know that all elements after 34 are greater than 15.
So swap the first element before 34 with the pivot.

So array looks like

7, -7, -13, 15, 34, 22, 19

Now all on left of 15 are lesser than 15 and all on right of 15 are greater than 15