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.
Solution: Binary Search
class Solution(object):
def search(self, nums, target):
"""
:type nums: List[int]
:type target: int
:rtype: int
"""
def binary_search(low, high):
if low > high:
return -1
mid = low + (high - low) / 2
if nums[mid] == target:
return mid
if nums[mid] > nums[high]:
if nums[low] <= target < nums[mid]:
return binary_search(low, mid - 1)
return binary_search(mid + 1, high)
if nums[mid] < target <= nums[high]:
return binary_search(mid + 1, high)
return binary_search(low, mid - 1)
return binary_search(0, len(nums) - 1)