leetcode81

class Solution:
    def search(self, nums: 'List[int]', target: int) -> bool:
        n = len(nums)
        if n == 0:
            return False
        if n == 1:
            return target == nums[0]
        l,h = 0,n-1
        while l <= h:
            mid = l + (h - l) // 2
            if nums[l] == target or nums[mid] == target or nums[h] == target:
                return True
            if nums[l] < nums[mid]:#左侧有序，以l为起点，以mid为终点
                if nums[l] < target and target < nums[mid]:
                    h = mid - 1
                else:
                    l = mid + 1
            elif nums[l] > nums[mid]:#右侧有序，以mid为起点，以h为终点
                if nums[mid] < target and target < nums[h]:
                    l = mid + 1
                else:
                    h = mid - 1
            else:#无法判断顺序，可以让h-1，也可以让l+1
                h -= 1
        return False