moonlightshadow123
6/21/2017 - 2:49 PM

268. Missing Number

  1. Missing Number
class Solution(object):
    def missingNumber(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        x = 0
        for i in range(len(nums)+1):
            x ^= i
        for i in nums:
            x ^= i
        return x

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.

For example, Given nums = [0, 1, 3] return 2.

Note: Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?