LeetCode - Search in Rotated Sorted Array

原题网址：

https://leetcode.com/problems/search-in-rotated-sorted-array/#/description

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.

代码：

用二分查找法解决，关键在于分情况讨论左边有序和右边有序时的情况。

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

while left <= right:
mid = left + ((right - left) >> 1)

if nums[mid] == target:
return mid
elif (nums[left] <= target < nums[mid]) or \
(nums[mid] < nums[left] and not (nums[mid] < target <= nums[right])):
right = mid - 1
else:
left = mid + 1

return -1