Done design-2

[pranjay01]

No description provided.

[super30admin]

Your solution for the queue using stacks is excellent. It correctly implements the required operations with the right time and space complexity. The code is clean and well-commented. Here are a few minor suggestions:

1. In the empty method, you can simplify the return statement to return not self.enteringStack and not self.outgoingStack. This is more idiomatic in Python and avoids calling len twice.

2. Although the problem states that all calls to pop and peek are valid, it's still a good practice to handle edge cases (like when both stacks are empty) in the pop and peek methods. However, since the problem guarantees valid calls, it's acceptable as is.

Overall, great job!

[super30admin]

Your solution for the queue using stacks is excellent. It correctly implements the FIFO queue using two stacks with amortized O(1) time complexity for operations. The code is clean and well-commented.

Strengths:

• You used descriptive variable names (enteringStack and outgoingStack) which make the code easy to understand.
• The readjustStacksIfNeeded method encapsulates the logic for transferring elements, which is a good practice for code modularity.
• You handled the constraints correctly, assuming that pop and peek are valid calls.

Areas for Improvement:

• In the empty method, you can directly check if both stacks are empty (like return not self.enteringStack and not self.outgoingStack) which is slightly more efficient than calculating the sum of lengths.
• Note that the problem states that all calls to pop and peek are valid, so you don't need to handle the case when the queue is empty in pop and peek. However, your solution already assumes that because you call readjustStacksIfNeeded without checking for emptiness. This is correct.

Regarding the HashMap solution: It is correct and efficient, but please note that the problem only asked for the queue implementation. Make sure to submit only the required solution unless otherwise specified.