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Arrays: Left Rotation

  • AffineStructure + 1 comment

    They have rotate built into the deque

    def array_left_rotation(a, n, k):
    a = deque(a)
    for i in range(k):
        a.rotate(-1)
    return a
    • josegabriel_st + 0 comments

      You have O(n) in:

      a = deque(a)

      In order to avoid this, you should use a deque from the beginning like:

      from collections import deque

def array_left_rotation(a, n, k):
    a.rotate(-k)

n, k = map(int, input().strip().split(' '))
a = deque(map(int, input().strip().split(' ')))
array_left_rotation(a, n, k);
print(*a, sep=' ')

      And array_left_rotation only takes O(k) instead of O(n).

      Note that a is pased by reference, so there is no need to return anything, but this could be an issue for some user cases, for this particular problem, it works.