[leetcode] Find Minimum in Rotated Sorted Array @ Python

source: https://oj.leetcode.com/problems/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

Complexity: O(logN)

 

class Solution:
    # @param num, a list of integer
    # @return an integer
    def findMin(self, num):
        min = num[0]
        start, end = 0, len(num) - 1
        while start <= end:
            mid = (start + end)/2
            if num[mid] >= min:
                start = mid + 1
            else:
                min = num[mid]
                end = mid
        return min