Left or Right rotation by two, three or N positions in an array using Python

• Input: [1, 2, 3, 4, 5, 6, 7, 8, 9]
• Output Left shift by 4: [5, 6, 7, 8, 9, 1, 2, 3, 4]
• Output Right shift by 5: [5, 6, 7, 8, 9, 1, 2, 3, 4]

 

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• Interviewer: Left shift by 4 and Right shift by 5

data = [1, 2, 3, 4, 5, 6, 7, 8, 9]
left_shifts = 4
right_shifts = 5

left = data[left_shifts:]+ data[:left_shifts]
right = data[-right_shifts:]+ data[:-right_shifts]

print("left: ", left)
print("right: ", right)

 

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• Interviewer: Left shift by 4 without slicing

data = [1, 2, 3, 4, 5, 6, 7, 8, 9]
shifts = 4

for shift in range(shifts):
    swap = data[0]
    for index in range(len(data)-1):
        data[index] = data[index+1]
    data[-1] = swap

print(data)

 

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• Interviewer: Right shift by 5 without slicing

data = [1, 2, 3, 4, 5, 6, 7, 8, 9]
shifts = 5

for shift in range(shifts):
    swap = data[-1]
    for index in range(len(data)-1, 0, -1):
        data[index] = data[index-1]
    data[0] = swap

print(data)

 

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