Array Rotation Techniques in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to rotate the array to the left by one position.

DSA Python

def rotate_left_by_one(arr):
    first = arr[0]
    for i in range(len(arr) - 1):
        arr[i] = arr[i[1]1]
    arr[-1] = first
    return arr

print(rotate_left_by_one([1, 2, 3, 4, 5]))

Drag options to blanks, or click blank then click option'

A+

B-

C*

D//

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' instead of '+' causes wrong indexing.

Using '*' or '//' causes syntax or runtime errors.

We add 1 to the current index to shift elements left by one.

2fill in blank

medium

Complete the code to rotate the array to the right by one position.

DSA Python

def rotate_right_by_one(arr):
    last = arr[-1]
    for i in range(len(arr) - 1, 0, [1]):
        arr[i] = arr[i - 1]
    arr[0] = last
    return arr

print(rotate_right_by_one([1, 2, 3, 4, 5]))

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A1

B-1

C0

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using positive step causes infinite loop or wrong rotation.

Using 0 as step causes error.

We use -1 to move backward through the array indices.

3fill in blank

hard

Fix the error in the code to rotate the array left by d positions using slicing.

DSA Python

def rotate_left(arr, d):
    n = len(arr)
    d = d % n
    rotated = arr[d:] + arr[1]d]
    return rotated

print(rotate_left([1, 2, 3, 4, 5], 2))

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A]

B[

C[-

D[:

Attempts:

3 left

💡 Hint

Common Mistakes

Missing ':' causes syntax error.

Using wrong slice indices causes wrong output.

The slice arr[:d] selects the first d elements to move to the end.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each element to its rotated position after left rotation by 1.

DSA Python

arr = [10, 20, 30, 40]
rotated_dict = {arr[i]: arr[(i [1] 1) [2] len(arr)] for i in range(len(arr))}
print(rotated_dict)

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A+

B-

C%

D//

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' instead of '+' causes wrong mapping.

Using '//' instead of '%' causes wrong index wrapping.

We add 1 to index i and use modulo to wrap around the array length.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps uppercase elements to their rotated values after right rotation by 2.

DSA Python

arr = ['a', 'b', 'c', 'd', 'e']
rotated_dict = {{
    arr[i].[1](): arr[(i [2] 2) [3] len(arr)]
    for i in range(len(arr))
}}
print(rotated_dict)

Drag options to blanks, or click blank then click option'

Aupper

B+

C%

Dlower

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lower' instead of 'upper' changes key case incorrectly.

Using '-' instead of '+' causes wrong rotation direction.

Using '//' instead of '%' causes wrong index wrapping.

Use upper() to capitalize keys, add 2 to index, and use modulo for wrapping.