Rotate Deque By K

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Time: O(k)

Space: O(1)

Intuition

Rotate a deque by k positions. Pop from front, push to back k times.

Algorithm

1For clockwise k rotation: move last k elements to front. Or rotate(deque, k) using deque operations.

Common Pitfalls

•Normalize k = k % size. Deque rotation in O(k) or O(n-k) depending on direction.

Rotate Deque By K.java

Java

// Approach: Pop k elements from front and add to back (or use modular arithmetic on index).
// Time: O(k) Space: O(1)
import java.util.*;

class Solution {
    public static void rotateDeque(Deque<Integer> dq, int type, int k) {
        while (k-- > 0) {
            if (type == 1)
                dq.addFirst(dq.pollLast());
            else
                dq.addLast(dq.pollFirst());
        }
    }
}

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