LeetCode 136. Single Number - Python

LeetCode 136. Single Number  - Python

 

Given a non-empty array of integers, every element appears twice except for one. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

 

Example 1:

Input: [2,2,1]
Output: 1

 

Example 2:

Input: [4,1,2,1,2]
Output: 4

 

 

 

Solution 1  :

class Solution:
    def singleNumber(self, nums: List[int]) -> int:
        cnt_dict = Counter(nums) 
        items = cnt_dict.items()
        
        for key, val in items:
            if val == 1:
                answer = key
                break
                
        return answer

Solution 2  :

class Solution:
    def singleNumber(self, nums: List[int]) -> int:
        answer = 0
        for i in nums:
            answer = answer ^ i
        return answer

 

 

 

 

 

내가 틀린 코드

n2 = map(int, input().split())
n2_list = list(n2)

for i in range(n2):
    if i != int(n2):
        continue
    print(i, end='')

 

 

참고 개념  :

countercollections 모듈 - Counter 

dictionary 의 key, value 를 출력 하는 방법. 

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