136. Single Number

class Solution:
    def singleNumber(self, nums: List[int]) -> int:
        nums.sort()
        for i in range(0,len(nums), 2):
            if len(nums) %2 != 0 and i+1==len(nums):
                return nums[i]
            
            if nums[i] == nums[i+1]:
                # return nums[i]
                continue
            else:
                return nums[i]
                
                
                
'''
Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

You must implement a solution with a linear runtime complexity and use only constant extra space.

 

Example 1:

Input: nums = [2,2,1]
Output: 1
Example 2:

Input: nums = [4,1,2,1,2]
Output: 4
Example 3:

Input: nums = [1]
Output: 1
 

Constraints:

1 <= nums.length <= 3 * 104
-3 * 104 <= nums[i] <= 3 * 104
Each element in the array appears twice except for one element which appears only once.

'''