154. Find Minimum in Rotated Sorted Array II

這題是一道followup的問(wèn)題，解法只是普通的二分法，只是如果有重復(fù)元素的時(shí)候，最壞的情況是 O(n)達(dá)不到log(n)的情況了

class Solution(object):
    def findMin(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if not nums:
            return None
        if len(nums) == 1:
            return nums[0]
        if nums[0] < nums[-1]:
            return nums[0]
        start = 0
        end = len(nums) - 1
        while start + 1 < end:
            mid = start + (end - start) / 2
            if nums[mid] > nums[end]:
                start = mid
            elif nums[mid] < nums[end]:
                end = mid
            else:
                end -= 1
        if nums[start] > nums[end]:
            return nums[end]
        else:
            return nums[start]