[Codility] Lesson-02.1: CyclicRotation
Handling the array with the cyclic rotation process is dealt with via this post. For accessing the cyclic rotation problem, you may click the following link.
Task Description
An array A consisting of N integers is given. Rotation of the array means that each element is shifted right by one index, and the last element of the array is moved to the first place. For example, the rotation of array A = [3, 8, 9, 7, 6] is [6, 3, 8, 9, 7] (elements are shifted right by one index and 6 is moved to the first place).
The goal is to rotate array A K times; that is, each element of A will be shifted to the right K times.
Write a function:
def solution(A, K)
that, given an array A consisting of N integers and an integer K, returns the array A rotated K times.
For example, given
A = [3, 8, 9, 7, 6]
K = 3
the function should return [9, 7, 6, 3, 8]. Three rotations were made:
[3, 8, 9, 7, 6] -> [6, 3, 8, 9, 7]
[6, 3, 8, 9, 7] -> [7, 6, 3, 8, 9]
[7, 6, 3, 8, 9] -> [9, 7, 6, 3, 8]
For another example, given
A = [0, 0, 0]
K = 1
the function should return [0, 0, 0]
Given
A = [1, 2, 3, 4]
K = 4
the function should return [1, 2, 3, 4]
Assume that:
- N and K are integers within the range [0..100];
- each element of array A is an integer within the range [−1,000..1,000].
In your solution, focus on correctness. The performance of your solution will not be the focus of the assessment.
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Key Point
- Checking the length of the array must be conducted first. If the array does not include any element, return them directly.
- Rotating (cycling) the array completely is not efficient. You can reduce unnecessary computation via this truth.
Solution (using Python)
def solution(A, K):
try: K = K % len(A)
except: return A
if(K == 0): return A
else:
B = A[-K:]
B.extend(A[:-K])
return BPlease use the above solution for reference.
I recommend you to write your own source code.
