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Bug Report for largest-unique-number #6119

Description

@vinylflamingo

Bug Report for https://neetcode.io/problems/largest-unique-number

Please describe the bug below and include any steps to reproduce the bug or screenshots if possible.

While working through this problem I created a stack solution that was accepted:

class Solution:
    def largestUniqueNumber(self, nums: List[int]) -> int:
        nums_stack = []
        nums.sort()
        last_num = -1
        for num in nums:
            if num not in nums_stack: 
                nums_stack.append(num)
                last_num = num
            elif num in nums_stack:
                nums_stack.pop()
                last_num = num
            elif num == last_num:
                continue 
            
        if len(nums_stack) > 0: 
            return nums_stack[-1]
        else: 
            return -1

This should not be accepted, because odd number groupings cause an append, pop, and append sequence where the number is still added to the stack

Proposing to change a test case where the largest number is a non-distinct odd group.
nums=[5,7,3,9,4,9,8,3,1,9]
or similiar

In this case three 9s would catch this. It passes previously, because any case of odd numbered groups was still lower than the highest distinct number. Passed by luck, but not actually correct.

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