136. Single Number

 Difficulty: Easy

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

Python Solution:

class Solution(object):

    def singleNumber(self, nums):

        nums.sort()

        i=0

        while 1:

            try:

                if nums[i]==nums[i+1]:

                    del nums[i]

                    del nums[i]

                else:

                    i+=1

            except:

                break

        return nums[0]