Quicksort

def partition(l, low, high):
    pivot = l[high]
    i = low - 1

    print(l)
    print("pivot = " + str(pivot))

    for j in range(low, high):
        if l[j] < pivot:
            i += 1
            swap(l, i, j)

        print("j = " + str(j) + ", i = " + str(i) )
        print(l)

    i += 1
    swap(l,i,high)
    print("i = " + str(i))
    print(l)
    print()
    return i


def quicksort(l, low, high):

    if low < high:
        pi = partition(l, low, high)
        quicksort(l, low, pi - 1)  #lato sinistro della lista
        quicksort(l, pi + 1, high) #lato destro della lista


def swap(l,i,j):
    temp = l[i]
    l[i] = l[j]
    l[j] = temp


l = [9, 5, 1, 3, 8, 6, 4, 7]
quicksort(l, 0, len(l) - 1)

print()
print("lista ordinata L = " + str(l))