268. Missing Number

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?

Answer with python:

class Solution(object):
def missingNumber(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
length = len(nums)
for i in range(0,length):
if nums[0] ==0:
return 1
else:
nums[i] != i
return nums[i-1]+1