bad_rotations_en.py

def rotate_slow_cheap(arr, k): #inputs are array and the number of steps to rotate to the right k
    n = len(arr)
    for i in range(k): #k times repeat 1-step rotation
        last_element = arr[-1] #the only additional memory - О(1)
        for j  in range(n-1,0,-1):#move the values, traversing from the end of the array
            arr[j] = arr[j-1]
        arr[0] = last_element
    #time complexity is O(n*k)
    return arr

print(rotate_slow_cheap(list(range(10)),3))
#Output: [7, 8, 9, 0, 1, 2, 3, 4, 5, 6]


def rotate_fast_expensive(arr, k): #inputs are array and the number of steps to rotate to the right k
    n = len(arr)
    saved_slice = arr[n-k:][:] #copy of the end of the array - O(k)
    for i in range(n-1, k-1, -1): #move elements k steps to the right
        arr[i] = arr[(i-k)%n]
    for i in range(k):
        arr[i] = saved_slice[i]
    #time complexity O(n)
    return arr

print(rotate_fast_expensive(list(range(10)),3))
#Output: [7, 8, 9, 0, 1, 2, 3, 4, 5, 6]