leetcode--Search in Rotated Sorted Array
来源:互联网 发布:最终幻想15剧情 知乎 编辑:程序博客网 时间:2024/06/14 01:08
Suppose a sorted array 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.
题意:假设一个数组经过旋转。给定一个元素,在旋转数组中找出其index,如果没有,返回-1
数组中没有重复元素
分类:数组,二分查找
解法1:二分查找。计算mid,首先判断mid是属于旋转数组的哪部分。
我们知道,旋转数组,{4,5,6,7}为一部分,递增,同理,{0,1,2}为一部分,递增。而后一部分,不可能大于前一部分
如果nums[mid]>nums[low],说明属于前一部分,否则是后一部分
判断是哪部分用户,判断target的位置
如果是第一部分,如果taget只有大于nums[low],小于nums[mid],才可能落在这个部分之内,这时可以更新high=mid-1
否则,在这部分外,更新low=mid+1;
对于第二部分,同理
public class Solution { public int search(int[] nums, int target) { int low = 0; int high = nums.length-1; while(low<=high){ int mid = (low+high)/2; if(nums[mid]==target) return mid; if(nums[mid]>=nums[low]){//如果mid属于左边 if(nums[mid]>target && nums[low]<=target){//如果target属于左边 high = mid-1; }else{ low = mid+1; } }else{//如果mid属于右边 if(target>nums[mid] && target<=nums[high]){ low = mid+1; }else{ high = mid-1; } } } return -1; }}
0 0
- [leetcode][search] Search in Rotated Sorted Array
- LeetCode: Search in Rotated Sorted Array
- LeetCode: Search in Rotated Sorted Array II
- LeetCode Search in Rotated Sorted Array
- LeetCode Search in Rotated Sorted Array II
- [Leetcode] Search in Rotated Sorted Array
- LeetCode : Search in Rotated Sorted Array
- LeetCode : Search in Rotated Sorted Array II
- [LeetCode] Search in Rotated Sorted Array II
- [LeetCode] Search in Rotated Sorted Array
- [Leetcode] Search in a Rotated Sorted Array
- [Leetcode] Search in Rotated Sorted Array II
- leetcode 97: Search in Rotated Sorted Array
- [LeetCode] Search in Rotated Sorted Array
- [leetcode] Search in Rotated Sorted Array
- [leetcode] Search in Rotated Sorted Array II
- Leetcode Search in Rotated Sorted Array
- [LeetCode]Search in Rotated Sorted Array
- Memcached源码分析(二)-jenkins hash函数
- 微软掷豪金投资海底数据电缆
- unity3d移动平台性能优化(14):渲染路径设置
- macvim 配置
- 第三题
- leetcode--Search in Rotated Sorted Array
- java中常用的工具类
- 事件驱动机制在单片机软件中的应用
- poj_Feel Good_单调栈
- Nginx系列(十一.nginx正向代理)
- 【Java-IO】Java文件操作
- Python判断当前操作系统类型以及os/sys/platform模块简介
- Selenium RC工作原理和测试案例
- 内存重叠之strcpy&memmove