[IMP] Design-2

[amitmittal117]

No description provided.

[super30admin]

Strengths:

• The code is clean and well-organized.
• The use of two stacks is correct and efficient.
• The comments are helpful.

Areas for improvement:

1. The size variable is not necessary. You can determine if the queue is empty by checking if both stacks are empty. This would save a little memory and avoid potential synchronization issues (though not critical here).
2. There is code duplication in pop and peek for transferring elements from in_stack to out_stack. You can create a helper method (e.g., _transfer()) to avoid duplication.
3. Although the problem states that all calls to pop and peek are valid, it's good practice to consider edge cases. However, for this problem, it's acceptable.

Suggested improvements:

• Remove the size variable and update the empty method to: return not self.in_stack and not self.out_stack.
• Create a helper method:

  def _transfer(self):
       if not self.out_stack:
           while self.in_stack:
               self.out_stack.append(self.in_stack.pop())

  Then call this helper in pop and peek.

Example revised code:

class MyQueue:
    def __init__(self):
        self.in_stack = []
        self.out_stack = []

    def push(self, x: int) -> None:
        self.in_stack.append(x)

    def pop(self) -> int:
        self._transfer()
        return self.out_stack.pop()

    def peek(self) -> int:
        self._transfer()
        return self.out_stack[-1]

    def empty(self) -> bool:
        return not self.in_stack and not self.out_stack

    def _transfer(self):
        if not self.out_stack:
            while self.in_stack:
                self.out_stack.append(self.in_stack.pop())