今天看到LeetCode OJ题目下方多了“Show Tags”功能。我觉着挺好,方便刚開始学习的人分类练习。同一时候也是解题时的思路提示。

【题目】

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.

【解法】

题目比較简单,直接看代码吧,可是要想把代码写得美丽并不easy啊。

O(n)非常好写,O(lgn)要好好捋捋思路。

public class Solution {
// O(n) simple
public int findMin1(int[] num) {
int len = num.length;
if (len == 1) {
return num[0];
} for (int i = 1; i < len; i++) {
if (num[i] < num[i-1]) {
return num[i];
}
} return num[0]; // 尼玛,看成找中间数了
// if (len % 2 != 0) { //len is odd
// return num[(begin+len/2)%len];
// } else { //len is even
// return (num[(begin+len/2-1)%len] + num[(begin+len/2)%len]) / 2;
// }
} // O(lgn) not that good
public int findMin2(int[] num) {
int len = num.length;
if (len == 1) return num[0]; int left = 0, right = len-1;
while (left < right) {
if ((right-left) == 1) return Math.min(num[left], num[right]); if (num[left] <= num[right]) return num[left]; int mid = (left + right) / 2;
if (num[mid] < num[right]) {
right = mid;
} else if (num[left] < num[mid]) {
left = mid;
}
} return num[left];
} // O(lgn) optimized iteratively
public int findMin3(int[] num) {
int len = num.length;
if (len == 1) return num[0];
int left = 0, right = len-1;
while (num[left] > num[right]) { // good idea
int mid = (left + right) / 2;
if (num[mid] > num[right]) {
left = mid + 1;
} else {
right = mid; // be careful, not mid-1, as num[mid] maybe the minimum
}
}
return num[left];
} // O(lgn) optimized recursively
public int findMin(int[] num) {
return find(num, 0, num.length-1);
} public int find(int[] num, int left, int right) {
if (num[left] <= num[right]) {
return num[left];
}
int mid = (left + right) / 2;
if (num[mid] > num[right]) {
return find(num, mid+1, right);
}
return find(num, left, mid);
}
}

【LeetCode】Find Minimum in Rotated Sorted Array 解题报告的更多相关文章

  1. 【LeetCode】153. Find Minimum in Rotated Sorted Array 解题报告(Python)

    [LeetCode]153. Find Minimum in Rotated Sorted Array 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode. ...

  2. LeetCode 新题: Find Minimum in Rotated Sorted Array 解题报告-二分法模板解法

    Find Minimum in Rotated Sorted Array Question Solution Suppose a sorted array is rotated at some piv ...

  3. LeetCode: Search in Rotated Sorted Array 解题报告

    Search in Rotated Sorted Array Suppose a sorted array is rotated at some pivot unknown to you before ...

  4. Leetcode Find Minimum in Rotated Sorted Array 题解

    Leetcode Find Minimum in Rotated Sorted Array 题目大意: 对一个有序数组翻转, 就是随机取前K个数,移动到数组的后面,然后让你找出最小的那个数.注意,K有 ...

  5. [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 ...

  6. [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 ...

  7. 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 ...

  8. 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 ...

  9. 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 ...

随机推荐

  1. WPF拖放功能实现

    写在前面:本文为即兴而作,因此难免有疏漏和词不达意的地方.在这里,非常期望您提供评论,分享您的想法和建议. 这是一篇介绍如何在WPF中实现拖放功能的短文. 首先要读者清楚的一件事情是:拖放主要分为拖放 ...

  2. Hibernate多对多两种情况

    Hibernate在做多对多映射的时候,除了原先的两张表外,会多出一个中间表做关联,根据中间表的会有两种不同的配置情况: 1.中间表不需要加入额外数据. 2.中间表有其他字段,需记录额外数据. 下面, ...

  3. Selenium2+python自动化65-js定位几种方法总结【转载】

    前言 本篇总结了几种js常用的定位元素方法,并用js点击按钮,对input输入框输入文本 一.以下总结了5种js定位的方法 除了id是定位到的是单个element元素对象,其它的都是elements返 ...

  4. python模块学习:Iterators和Generators

    转自:http://www.cnblogs.com/zhbzz2007/p/6102695.html 1 迭代器: 迭代器,允许你在一个容器上进行迭代的对象. python的迭代器主要是通过__ite ...

  5. 2017/3/7 值得"纪念"的错误

    使用viewpager和fragment做个能左右滑动的效果,结果怎么弄怎么有问题,先是怀疑什么viewPager维护刷新内部fragment什么的,又是在FragmentPageAdapter的ge ...

  6. 最近项目中用到的js

    1.用字典判断数组是否有重复function ticketTypeValidate() { var ticketArr = []; var tickettype = $("div[name= ...

  7. Maven学习笔记2

    Maven安装配置 1.下载Maven 官方地址:http://maven.apache.org/download.cgi 将下载的压缩包解压到你要安装 Maven 的文件夹.假设你解压缩到文件夹 – ...

  8. (寒假开黑gym)2018 USP Try-outs

    layout: post title: (寒假开黑gym)2018 USP Try-outs author: "luowentaoaa" catalog: true tags: m ...

  9. POJ 3026 --Borg Maze(bfs,最小生成树,英语题意题,卡格式)

    Borg Maze Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16625   Accepted: 5383 Descri ...

  10. 去掉Chrome手机版首屏的“推荐的文章”

    百度可得很多类似的文章,然而都是失效的,,比如此文,本文演示所使用的Chrome版本为59. 百度所得的解决办法都是同一个,排版,截图都是一样的,害我浪费了不少力气. 第一,转载文章未标明文章出处: ...