Given an array containing n distinct numbers taken from 0, 1, 2, ..., n
, find the one that is missing from the array.
Example 1:
Input: [3,0,1] Output: 2
Example 2:
Input: [9,6,4,2,3,5,7,0,1] Output: 8
Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?
class Solution(object): def missingNumber(self, nums): """ :type nums: List[int] :rtype: int """ if 0 not in nums: return 0 m=max(nums) s=sum(nums) ms=(m+1)*m/2 if ms==s: return m+1 return (m+1)*m/2-sum(nums)