How do you rotate an array by k positions? (In-place vs extra space)

Difficulty: 3/10

array manipulation, in-place algorithms, time/space complexity

Array Rotation

For right rotation by k positions, first reduce k using k modulo n. An efficient in-place approach uses three reversals: reverse the entire array, reverse the first k elements, then reverse the remaining elements.

javascript

1
Time complexity: O(n).
2
Extra space: O(1) for the reversal approach.
3
An extra-array approach is simpler but requires O(n) additional space.
4
For very large k, k % n avoids unnecessary rotations.
5
The direction of rotation must be defined clearly.

Scenario Questions

0-2 years experience

Follow-up Questions