Lists: Difficult Solutions

List functions

Draw out a box and pointer diagram for lst1 and lst2.

lst1 = [1, 2, 3, 4]
lst2 = [5, 6, 7, 8]
lst1[lst2[0] - lst1[1]] = lst2
lst2.append(lst1.remove(2))
Screen Shot 2019-01-13 at 3.11.52 PM.png 
lst1.extend([lst2[len(lst1)]])
lst2.append([lst1[len(lst1) - lst1[2][0] + lst1[lst1[0]]]])
Screen Shot 2019-01-13 at 3.22.26 PM.png

code writing

Write a function that will take in a list and sort it using quicksort. Quicksort takes the first element and partitions the list into three partitions: elements less than the first element, elements equal to the first element, and elements greater than the first element. Then it recursively applies those steps to the partitions.
def quicksort(lst):
>>> lst = [4, 6, 7, 2, 1, 3]
>>> quicksort(lst)
[1, 2, 3, 4, 6, 7]
    if lst == []:
        return []
    less = [x for x where x < lst[0]]
    equal = [x for x where x == lst[0]]
    greater = [x for x where x > lst[0]]
    less = quicksort(less)
    greater = quicksort(greater)
    return less + equal + greater