题目描述:
python实现 Search in Rotated Sorted Array 搜索旋转排序数组
中文:假设按照升序排序的数组在预先未知的某个点上进行了旋转。
( 例如,数组 [0,1,2,4,5,6,7] 可能变为 [4,5,6,7,0,1,2] )。
搜索一个给定的目标值,如果数组中存在这个目标值,则返回它的索引,否则返回 -1 。
你可以假设数组中不存在重复的元素。
你的算法时间复杂度必须是 O(log n) 级别。
英文:Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).
You are given a target value to search. If found in the array return its index, otherwise return -1.
You may assume no duplicate exists in the array.
Your algorithm‘s runtime complexity must be in the order of O(log n).
1 class Solution(object): 2 def search(self, nums, target): 3 """ 4 :type nums: List[int] 5 :type target: int 6 :rtype: int 7 """ 8 start = 0 9 end = len(nums)-1 10 while start<=end: 11 mid = (start + end)/2 #对于整数会自动省去小数部分 12 if nums[mid] == target: 13 return mid 14 if nums[mid]>=nums[start]: 15 if target >= nums[start] and target<=nums[mid]: 16 end = mid-1 17 else: 18 start = mid + 1 19 20 if nums[mid]<nums[end]: 21 if target > nums[mid] and target<=nums[end]: 22 start = mid+1 23 24 else: 25 end = mid -1 26 return -1
题目来源:力扣题库
原文地址:https://www.cnblogs.com/spp666/p/11536041.html
时间: 2024-10-10 12:03:44