CC - 10

[shinjaneegupta]

No description provided.

[super30admin]

Interview Problem : Buy and Sell Stock (BuyAndSellStock2.py)

Your response should be comprehensive and helpful for the student to understand their mistakes and learn from them.

VERDICT: NEEDS_IMPROVEMENT

---

Interview Problem: Peeking Iterator (PeekingIterator.py)

Your solution is almost correct and follows a similar approach to the reference solution. However, there is a critical bug in the next() method: when peek_val is 0 (which is a valid integer), the condition if self.peek_val: evaluates to False, so it will not return the stored 0 and instead call the iterator's next() method. This is incorrect. You should change the condition to explicitly check for None, i.e., if self.peek_val is not None:. Similarly, in the hasNext() method, you correctly use self.peek_val is not None, which is good.

Also, in the next() method, when peek_val is not None, you should store it in a temporary variable (like to_return), set peek_val to None, and then return the temporary variable. This part is correct, but the condition needs to be fixed.

Another minor point: the variable name it_ is not very descriptive. You could name it iterator for clarity, but this is a style choice.

To fix the issue, update the next() method as follows:

    def next(self):
        if self.peek_val is not None:
            to_return = self.peek_val
            self.peek_val = None
            return to_return
        return self.it_.next()

With this change, the solution will handle all integers correctly.

VERDICT: NEEDS_IMPROVEMENT