LeetCode-Find Minimum in Rotated Sorted Array I & II

153. Find Minimum in Rotated Sorted Array

Suppose a sorted array 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.

You may assume no duplicate exists in the array.

Solution

# binary search
class Solution(object):
    def findMin(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        low = 0
        high = len(nums) - 1
        while low < high:
            mid = (low + high)/2
            if nums[mid] < nums[high]:
                high = mid
            elif nums[mid] > nums[high]:
                low = mid + 1
        return nums[low]

154. Find Minimum in Rotated Sorted Array II

Follow up for "Find Minimum in Rotated Sorted Array":
What if duplicates are allowed?
Would this affect the run-time complexity? How and why?

Suppose a sorted array 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.

Solution

class Solution(object):
    def findMin(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        low = 0
        high = len(nums) - 1
        while low < high:
            mid = low + (high - low)/2
            if nums[mid] > nums[high]:
                low = mid + 1
            elif nums[mid] < nums[high]:
                high = mid
            else:
                high -= 1 
        return nums[low]