在升序數組中找到目標值的索引：

輸入: nums = [1,3,5,6], target = 5
輸出: 2

class Solution:def searchTarget(self, nums: List[int], target: int) -> int:left = 0right = len(nums)-1while left<=right:mid = left + (right - left) // 2if nums[mid] == target:return midelif nums[mid] > target:right = mid - 1else:left = mid + 1

在升序數組中找到目標值，如果沒有目標值，返回插入位置索引：

輸入: nums = [1,3,5,6], target = 2
輸出: 1

class Solution:def searchInsert(self, nums: List[int], target: int) -> int:left = 0right = len(nums)-1while left<=right:mid = left + (right - left) // 2if nums[mid] == target:return midelif nums[mid] > target:right = mid - 1else:left = mid + 1return left

在升序數組中找到目標值，返回左側邊界：

輸入: nums = [1,3,3,3,3,5,6], target = 3
輸出: 1

class Solution:def searchRange(self, nums, target):left = 0right = len(nums)-1while(left<=right):mid = left + (right-left)//2if nums[mid] == target:right = mid - 1elif nums[mid] > target:right = mid - 1else:left = mid + 1if left>=len(nums) or nums[left]!=target:return -1return left

在升序數組中找到目標值，返回右側邊界：

輸入: nums = [1,3,3,3,3,5,6], target = 3
輸出: 4

class Solution:def searchRightBound(self, nums, target):left = 0right = len(nums)-1while(left<=right):mid = left + (right-left)//2if nums[mid] == target:left = mid + 1elif nums[mid] > target:right = mid - 1else:left = mid + 1if nums[right]!=target or right>len(nums)-1:return -1return right

在升序數組中找到目標值，同時返回左右側邊界：

輸入：nums = [5,7,7,8,8,10], target = 8
輸出：[3,4]

class Solution:def searchRange(self, nums: List[int], target: int) -> List[int]:left = 0right = len(nums)-1res = [0,0]if target not in nums:return [-1,-1]# 尋找左側邊界while(left<=right):mid = left + (right-left)//2if nums[mid] == target:right = mid - 1elif nums[mid] > target:right = mid - 1else:left = mid + 1if left>=len(nums) or nums[left]!=target:res[0] = -1res[0] = left# 尋找右側邊界right = len(nums)-1while left<=right:mid = left+(right-left)//2if nums[mid]==target:left = mid + 1elif nums[mid]>target:right = mid - 1else:left = mid + 1if right<0 or nums[right]!=target:res[1] = -1res[1] = rightreturn res

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