@Phrancis/

# Array Rotations

## No description

Files
• main.py
main.py
```1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
```
```#!/bin/python3

def rotate_right(array:list, rotate_by:int = 1) -> list:
'''
Default behavior:
Given input [1,2,3] return [3,1,2]
Supplying a rotate_by value other than 1 will increase the number
of positions the values are moved towards the right by.
'''
if rotate_by < 0:
return rotate_left(array, - rotate_by)
array_length = len(array)
rotate_by = minimize_rotations(array_length, rotate_by)
return [array[i - rotate_by] for i in range(array_length)]

def rotate_left(array:list, rotate_by:int = 1) -> list:
'''
Default behavior:
Given input [1,2,3] return [2,3,1]
Supplying a rotate_by value other than 1 will increase the number
of positions the values are moved towards the left by.
'''
if rotate_by < 0:
return rotate_right(array, - rotate_by)
array_length = len(array)
rotate_by = minimize_rotations(array_length, rotate_by)
rotated = []
for i in range(array_length):
val_index = i + rotate_by
if val_index >= array_length:
val_index -= array_length
rotated.append(array[val_index])
return rotated

def minimize_rotations(array_length:int, rotate_by:int) -> int:
while rotate_by >= array_length:
rotate_by -= array_length
return rotate_by

def main():
# Testing code
arr = [1,2,3,4,5,6,7,8]
rotate_by = 1
print('Input array:', arr)
print('Rotate by:', rotate_by)
arr_L = arr_R = arr
print('Rotate left:')
for _ in range(len(arr)):
arr_L = rotate_left(arr_L, rotate_by)
print(arr_L)
print('Rotate right:')
for _ in range(len(arr)):
arr_R = rotate_right(arr_R, rotate_by)
print(arr_R)

main()```