给你一个按照非递减顺序排列的整数数组 nums,和一个目标值 target。请你找出给定目标值在数组中的开始位置和结束位置。
如果数组中不存在目标值 target,返回 [-1, -1]。
你必须设计并实现时间复杂度为 O(log n) 的算法解决此问题。
示例 1:
输入:nums = [5,7,7,8,8,10], target = 8
输出:[3,4]
示例 2:
输入:nums = [5,7,7,8,8,10], target = 6
输出:[-1,-1]
示例 3:
输入:nums = [], target = 0
输出:[-1,-1]
提示:
0 <= nums.length <= 105
-109 <= nums[i] <= 109
nums 是一个非递减数组
-109 <= target <= 109
通过次数738,276提交次数1,740,701
答案
class Solution:
def searchRange(self, nums: List[int], target: int) -> List[int]:
left = 0
right = len(nums)-1
ls = []
while left <= right:
middle = left + (right-left)//2
if nums[middle] < target:
left = middle + 1
elif nums[middle] > target:
right = middle - 1
elif nums[middle] == target:
right = middle - 1
if left >= len(nums) or nums[left] != target:
ls.append(-1)
else:
ls.append(left)
left = 0
right = len(nums)-1
while left <= right:
middle = left + (right-left)//2
if nums[middle] < target:
left = middle + 1
elif nums[middle] > target:
right = middle - 1
elif nums[middle] == target:
left = middle + 1
if right < 0 or nums[right] != target:
ls.append(-1)
else:
ls.append(right)
return ls