day5

Question:
05. Find Minimum in Rotated Sorted Array
Description
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.

Example
Given [4, 5, 6, 7, 0, 1, 2] return 0

oj:https://www.lintcode.com/problem/find-minimum-in-rotated-sorted-array/description
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answer:
class Solution:
    """
    @param nums: a rotated sorted array
    @return: the minimum number in the array
    """
    def findMin(self, nums):
        if not nums:
            return -1
            
        start, end = 0, len(nums) - 1
        while start + 1 < end:
            mid = (start + end) // 2
            if nums[mid] > nums[end]:
                start = mid
            else:
                end = mid
                
        return min(nums[start], nums[end])