What is the time complexity of various data structure operations?

The time complexity of various data structure operations can vary depending on the specific data structure being used. Here are the average time complexities for common data structure operations:

1. Array:
- Accessing an element by index: O(1)
- Inserting or deleting an element at the end: O(1)
- Inserting or deleting an element at the beginning or middle: O(n)

2. Linked List:
- Accessing an element by index: O(n)
- Inserting or deleting an element at the beginning: O(1)
- Inserting or deleting an element at the end: O(n)
- Inserting or deleting an element in the middle: O(n)

3. Stack:
- Push (inserting an element): O(1)
- Pop (deleting an element): O(1)
- Peek (accessing the top element): O(1)

4. Queue:
- Enqueue (inserting an element): O(1)
- Dequeue (deleting an element): O(1)
- Peek (accessing the front element): O(1)

5. Binary Search Tree:
- Searching for an element: O(log n) (average case), O(n) (worst case)
- Inserting or deleting an element: O(log n) (average case), O(n) (worst case)

6. Hash Table:
- Inserting or accessing an element: O(1) (average case), O(n) (worst case)
- Deleting an element: O(1) (average case), O(n) (worst case)

It's important to note that these time complexities are average or worst-case scenarios and can vary depending on the specific implementation and the size of the data structure.