【leetcode】1228.Missing Number In Arithmetic Progression

题目如下:

 

解题思路:题目很简单。先对数组排序,根据最大值和最小值即可求出公差,然后遍历数组,计算相邻元素的差,如果差不等于公差,即表示数字缺失。

代码如下:

class Solution(object):
    def missingNumber(self, arr):
        """
        :type arr: List[int]
        :rtype: int
        """
        arr.sort()
        diff = (arr[-1] - arr[0])/(len(arr))
        for i in range(len(arr)-1):
            if arr[i] + diff != arr[i+1]:
                return arr[i] + diff
        return arr[0]
        

 

posted @ 2019-10-21 14:41  seyjs  阅读(434)  评论(0编辑  收藏  举报