Description
There is an integer array nums
sorted in non-decreasing order (not necessarily with distinct values).
Before being passed to your function, nums
is rotated at an unknown pivot index k
(0 <= k < nums.length
) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]]
(0-indexed). For example, [0,1,2,4,4,4,5,6,6,7]
might be rotated at pivot index 5
and become [4,5,6,6,7,0,1,2,4,4]
.
Given the array nums
after the rotation and an integer target
, return true
if target
is in nums
, or false
if it is not in nums
.
You must decrease the overall operation steps as much as possible.
Β
Example 1:
Input: nums = [2,5,6,0,0,1,2], target = 0 Output: true
Example 2:
Input: nums = [2,5,6,0,0,1,2], target = 3 Output: false
Β
Constraints:
1 <= nums.length <= 5000
-104 <= nums[i] <= 104
nums
is guaranteed to be rotated at some pivot.-104 <= target <= 104
Β
Follow up: This problem is similar toΒ Search in Rotated Sorted Array, butΒ nums
may contain duplicates. Would this affect the runtime complexity? How and why?
Solution
Python3
class Solution:
def search(self, nums: List[int], target: int) -> bool:
N = len(nums)
if N == 0: return False
left, right = 0, N - 1
while left <= right:
while left < right and nums[left] == nums[left + 1]:
left += 1
while left < right and nums[right] == nums[right - 1]:
right -= 1
mid = left + (right - left) // 2
if nums[mid] == target:
return True
elif nums[left] <= nums[mid]:
if target <= nums[mid] and target >= nums[left]:
right = mid - 1
else:
left = mid + 1
else:
if target >= nums[mid] and target <= nums[right]:
left = mid + 1
else:
right = mid - 1
return False