Leetcode/33.py at master · ketulsuthar/Leetcode · GitHub

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'''

33. Search in Rotated Sorted Array

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]).

You are given a target value to search. If found in the array return its index, otherwise return -1.

You may assume no duplicate exists in the array.

Your algorithm's runtime complexity must be in the order of O(log n).

Example 1:

Input: nums = [4,5,6,7,0,1,2], target = 0
Output: 4
Example 2:

Input: nums = [4,5,6,7,0,1,2], target = 3
Output: -1


'''


class Solution(object):
    def search(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: int
        """
        l = 0
        r = len(nums)-1

        while l <= r:
            m = (l+r) // 2
            lv,rv,mv = nums[l],nums[r],nums[m]

            if mv == target: return m

            if lv <= mv:
                if lv <= target < mv:
                    r = m-1
                else:
                    l = m+1
            else:
                if mv < target <= rv:
                    l = m+1
                else:
                    r = m-1

        return -1