leetcode刷题记录15

介绍15

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?

思路15

等差数列

代码15

class Solution(object):
    def missingNumber(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        s=sum(nums)
        n=max(nums)
        if min(nums)!=0:
            return 0
        else:
            if n*(n+1)/2-s==0:
                return n+1
            else:
                return n*(n+1)/2-s