[LeetCode] Third Maximum Number

🔍  문제

Given an integer array nums, return the third distinct maximum number in this array. If the third maximum does not exist, return the maximum number.

Input: nums = [3,2,1]
Output: 1
Explanation:
The first distinct maximum is 3.
The second distinct maximum is 2.
The third distinct maximum is 1.

 

🖥  실행

1) Answer

class Solution:
    def thirdMax(self, nums: List[int]) -> int:
        for i in nums:
            while nums.count(i) > 1:
                nums.remove(i)
        
        nums.sort(reverse=True)
        
        if len(nums)>2:
            return nums[2]
        else:
            return max(nums)

 

2) Better Solution

class Solution(object):
    def thirdMax(self, nums):
        v = [float('-inf'), float('-inf'), float('-inf')]
        for num in nums:
            if num not in v:
                if num > v[0]:   v = [num, v[0], v[1]]
                elif num > v[1]: v = [v[0], num, v[1]]
                elif num > v[2]: v = [v[0], v[1], num]
        return max(nums) if float('-inf') in v else v[2]