Implement a Resizable Deque
Implement a Resizable Deque
Design and implement a double-ended queue (deque) data structure that uses a circular array as its underlying storage. The deque must support efficient insertion and removal operations from both its front and back ends.
Core Functionality
Your implementation must provide the following operations:
pushFront(value): Insertsvalueat the front of the deque.pushBack(value): Insertsvalueat the back of the deque.popFront(): Removes and returns the element from the front of the deque. If the deque is empty, an appropriate error or exception should be handled.popBack(): Removes and returns the element from the back of the deque. If the deque is empty, an appropriate error or exception should be handled.peekFront(): Returns the element at the front of the deque without removing it.peekBack(): Returns the element at the back of the deque without removing it.isEmpty(): Returnstrueif the deque contains no elements,falseotherwise.size(): Returns the total number of elements currently stored in the deque.
Implementation Requirements
- Underlying Storage: Utilize a fixed-size array as the primary storage mechanism.
- Circular Array Logic: Implement the array as a circular buffer to ensure efficient
O(1)access and modification at both ends. - Automatic Resizing: When the underlying array becomes full, the deque must automatically resize. This involves allocating a new, larger array, copying all existing elements from the old array into the new one in their logical deque order, and correctly updating all internal pointers (e.g., front, back, capacity).
- Time Complexity: All required operations (
pushFront,pushBack,popFront,popBack,peekFront,peekBack,isEmpty,size) must achieveO(1)amortized time complexity.
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Core dilemma
The central engineering conflict is balancing dynamic capacity management and circular array indexing while strictly maintaining O(1) amortized time complexity for all deque operations. This involves correctly handling wrap-around logic and efficient resizing without breaking performance guarantees or data integrity.
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Implement a Resizable Deque
Implement a Resizable Deque
Design and implement a double-ended queue (deque) data structure that uses a circular array as its underlying storage. The deque must support efficient insertion and removal operations from both its front and back ends.
Core Functionality
Your implementation must provide the following operations:
pushFront(value): Insertsvalueat the front of the deque.pushBack(value): Insertsvalueat the back of the deque.popFront(): Removes and returns the element from the front of the deque. If the deque is empty, an appropriate error or exception should be handled.popBack(): Removes and returns the element from the back of the deque. If the deque is empty, an appropriate error or exception should be handled.peekFront(): Returns the element at the front of the deque without removing it.peekBack(): Returns the element at the back of the deque without removing it.isEmpty(): Returnstrueif the deque contains no elements,falseotherwise.size(): Returns the total number of elements currently stored in the deque.
Implementation Requirements
- Underlying Storage: Utilize a fixed-size array as the primary storage mechanism.
- Circular Array Logic: Implement the array as a circular buffer to ensure efficient
O(1)access and modification at both ends. - Automatic Resizing: When the underlying array becomes full, the deque must automatically resize. This involves allocating a new, larger array, copying all existing elements from the old array into the new one in their logical deque order, and correctly updating all internal pointers (e.g., front, back, capacity).
- Time Complexity: All required operations (
pushFront,pushBack,popFront,popBack,peekFront,peekBack,isEmpty,size) must achieveO(1)amortized time complexity.