LeetCode153:Find Minimum in Rotated Sorted Array
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
Find the minimum element.
You may assume no duplicate exists in the array.
不知道这道题为什么难度是Medium,感觉蛮简单的。
仅仅须要找到第一个大于它后面的数,它后面的数就是旋转排序数组中最小的数。
将返回结果初始化为数组中的第一个元素。这样就能够将结果统一起来。
时间复杂程度是O(N)。
runtime:4ms
class Solution {
public:
int findMin(vector<int>& nums) {
int result=nums[0];
auto iter=nums.begin();
for(;iter!=nums.end()-1;iter++)
{
if(*iter>*(iter+1))
{
result=*(iter+1);
break;
} }
return result;
}
};
然后看了下Discuss,发现了一个使用二分查找思想的代码。漫有意思的,也有分析。以后在碰到排序好的数组进行了一些变形或一些附加说明时注意使用二分查找的思想。时间复杂程度是O(logN)。
In this problem, we have only three cases.
Case 1. The leftmost value is less than the rightmost value in the list: This means that the list is not rotated. e.g> [1 2 3 4 5 6 7 ]
Case 2. The value in the middle of the list is greater than the leftmost and rightmost values in the list. e.g> [ 4 5 6 7 0 1 2 3 ]
Case 3. The value in the middle of the list is less than the leftmost and rightmost values in the list. e.g> [ 5 6 7 0 1 2 3 4 ]
As you see in the examples above, if we have case 1, we just return the leftmost value in the list. If we have case 2, we just move to the right side of the list. If we have case 3 we need to move to the left side of the list.
Following is the code that implements the concept described above.
int findMin(vector<int>& nums) {
int left = 0, right = nums.size() - 1;
while(left < right) {
if(nums[left] < nums[right])
return nums[left]; int mid = (left + right)/2;
if(nums[mid] > nums[right])
left = mid + 1;
else
right = mid;
} return nums[left];
}
LeetCode153:Find Minimum in Rotated Sorted Array的更多相关文章
- LeetCode153 Find Minimum in Rotated Sorted Array. LeetCode162 Find Peak Element
二分法相关 153. Find Minimum in Rotated Sorted Array Suppose a sorted array is rotated at some pivot unkn ...
- Leetcode153. Find Minimum in Rotated Sorted Array寻找旋转排序数组中最小值
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] ). 请找出其中最小的元素. 你可以假设数组中不存在重 ...
- [LeetCode] Find Minimum in Rotated Sorted Array II 寻找旋转有序数组的最小值之二
Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed? Would ...
- [LeetCode] Find Minimum in Rotated Sorted Array 寻找旋转有序数组的最小值
Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 migh ...
- 【leetcode】Find Minimum in Rotated Sorted Array I&&II
题目概述: Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 ...
- Leetcode | Find Minimum in Rotated Sorted Array I && II
Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 migh ...
- LeetCode Find Minimum in Rotated Sorted Array II
原题链接在这里:https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii/ 题目: Follow up for &qu ...
- LeetCode Find Minimum in Rotated Sorted Array
原题链接在这里:https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/ Method 1 就是找到第一个违反升序的值,就 ...
- Find Minimum in Rotated Sorted Array II
Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed? Would ...
随机推荐
- 《疯狂java讲义》笔记 1-5章
1.编译语言和解释语言理解,摘自李刚老师的<疯狂Java讲义>第三版: 就是说,Java和.net都是编译型有事解释型语言.编译型就是根据不同平台编译成不同的可执行机器码,编译过程中会进行 ...
- PHP5.6.x的新鲜事
PHP5.6.x的新鲜事 期中考回来,刷刷php.net,发现——又更新了..现在马上来看一下What's New in PHP 5.6.x 内部操作符重载(internal-operator-ove ...
- Java中double类型的数据精确到小数点后两位
Java中double类型的数据精确到小数点后两位 多余位四舍五入,四种方法 一: double f = 111231.5585;BigDecimal b = new BigDecimal(f); d ...
- bzoj 2852: 强大的区间 辗转相除
2852: 强大的区间 Time Limit: 5 Sec Memory Limit: 128 MBSubmit: 45 Solved: 12[Submit][Status][Discuss] D ...
- 移动应用产品开发-android开发(二)
这段时间实在太忙了,也没什么精力来写博客,还是没养成写博客的习惯,还是得记载下来,不然时间久了就忘记了. 早上一大早就来公司了,趁还早,拟定今天的工作内容和计划后,赶紧记载点东西. 最近做androi ...
- OA学习笔记-010-Struts部分源码分析、Intercepter、ModelDriver、OGNL、EL
一.分析 二. 1.OGNL 在访问action前,要经过各种intercepter,其中ParameterFilterInterceptor会把各咱参数放到ValueStack里,从而使OGNL可以 ...
- 被忽视的eMMC——A1 SD Bench闪存测试
一直以来,大家对手机的配置方面都比较关注CPU和GPU的架构.频率.核心数等,却经常忽略了手机闪存的速度.实际上手机的闪存素质对手机日常操作的响应.载入速度同样起到举足轻重的影响,今天给大家介绍的则是 ...
- android学习——项目的目录结构
学习开发之前要了解工程目录下的文件夹下文件的用意,是以HelloWorld为例: 1.HelloWorld项目的目录结构 1.1.src文件夹 1.2.gen文件夹 1.3.Android 2.1文件 ...
- UNion ALL 和 UNION 的区别
UNION: 指定合并多个结果集并将其作为单个结果集返回.ALL: 将全部行并入结果中.其中包括重复行.如果未指定该参数,则删除重复行.
- Ubuntu下安装mysql-python包
sudo apt-get install libmysqld-dev sudo apt-get install libmysqlclient-dev sudo apt-get install py ...