采用二分查找找出某个数字的下标

作者: 扯淡的青春26357104
来源: 51数据库
2022-08-12

class Solution(object):
    def searchRange(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        def binary_search(start,end,value):
            while end>=start:
                mid = (start+end)//2
                print(mid)
                if nums[mid]>target:
                    end = mid-1
                elif nums[mid]<target:
                    start = mid+1
                else: 
                    if value==-1:
                        if mid-1>=start and nums[mid+value] == target:
                            end = mid+value
                        else:
                            return mid
                    else:
                        if mid+1<=end and nums[mid+value] == target:
                            start = mid+value
                        else:
                            return mid

            return -1
        a=binary_search(0,len(nums)-1,-1)
        b=binary_search(0,len(nums)-1,1)
        return [a,b]
a = Solution()
l = [2,2]
print(a.searchRange(l,2))

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