class Solution: def search(self, nums: List[int], target: int) -> int: #查找nums数组中target出现的下标位置,若target不在nums中,返回-1 def searchN(nums, target): left, right = 0, len(nums)-1 while left<=right: mid = (left+right)//2 if nums[mid]==target: return mid elif nums[mid]>target: right = mid-1 else: left = mid+1 return -1 #nums数组中可能存在重复数组,若target在nums中,返回第一次出现的位置,否则返回-1 def searchFirstN(nums, target): left, right = 0, len(nums)-1 while left<=right: mid = (left+right)//2 if nums[mid]==target: if mid==0 or nums[mid-1]!=target: return mid else: right = mid-1 elif nums[mid]>target: right = mid-1 else: left =mid+1 return -1 #nums数组中可能存在重复数组,若target在nums中,返回最后一次出现的位置,否则返回-1 def searchLastN(nums, target): left, right = 0, len(nums)-1 while left<=right: mid = (left+right)//2 if nums[mid]==target: if mid==len(nums)-1 or nums[mid+1]!=target: return mid else: left = mid+1 elif nums[mid]>target: right = mid-1 else: left =mid+1 return -1 #查找nums数组中第一个大于等于target的下标位置.否则返回-1(表示数组中的数均小于target) def searchFirstUpperN(nums, target): left, right = 0, len(nums)-1 while left<=right: mid = (left+right)//2 if nums[mid]>=target: if mid==0 or nums[mid-1]<target: return mid #缩小边界,往左寻找 right = mid-1 else: left = mid+1 return -1 #查找nums数组中最后一个小于等于target的下标位置,否则返回-1(nums数组中数字均大于target) def searchLastLessN(nums, target): left, right = 0, len(nums)-1 while left<=right: mid = (left+right)//2 if nums[mid]<=target: if mid==len(nums)-1 or nums[mid+1]>target: return mid left = mid+1 else: right = mid-1 return -1 return searchN(nums, target)