154. Find Minimum in Rotated Sorted Array II

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).

Find the minimum element.

The array may contain duplicates.

Example 1:

Input: [1,3,5]

Output: 1

Example 2:

Input: [2,2,2,0,1]

Output: 0

Note:

• This is a follow up problem to Find Minimum in Rotated Sorted Array.
• Would allow duplicates affect the run-time complexity? How and why? -This affects the worst case complexity to be O(n) since the each iteration the input size at worst only shrink one step (nums[mid] == nums[right])

Thoughts:

1. Handle duplicates: if (nums[mid] == nums[right], then nums[mid] maintains the value and right can only reduce one.

Code

class Solution(object):
def findMin(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
left, right = 0, len(nums) - 1
while left < right:
mid = (right - left >> 1) + left
if  nums[mid] < nums[right]:
right = mid

elif nums[mid] > nums[right]:
left = mid + 1

else:
right -= 1

return nums[left] # left = right