Java BinarySearch
Java BinarySearch
/**
* <html>
* <body>
* <P> Copyright 1994-2018 JasonInternational </p>
* <p> All rights reserved.</p>
* <p> Created on 2018年4月10日 上午9:46:32</p>
* <p> Created by Jason</p>
* </body>
* </html>
*/
package cn.ucaner.algorithm.search; /**
* In computer science, binary search, also known as half-interval search or logarithmic search, is a search algorithm that finds the position of a target value within a sorted array. Binary search
* compares the target value to the middle element of the array; if they are unequal, the half in which the target cannot lie is eliminated and the search continues on the remaining half until it is
* successful or the remaining half is empty.
* <p>
* Worst-case performance O(log n)<br>
* Best-case performance O(1)<br>
* Average performance O(log n)<br>
* Worst-case space complexity O(1)<br>
* <p>
* @see <a href="https://en.wikipedia.org/wiki/Binary_search_algorithm">Binary Search (Wikipedia)</a>
* <br>
* @author Justin Wetherell <phishman3579@gmail.com>
*/
public class BinarySearch { private static final int SWITCH_TO_BRUTE_FORCE = 200; private static int[] sorted = null; // Assuming the array is sorted
public static final int find(int value, int[] array, boolean optimize) {
BinarySearch.sorted = array;
try {
return recursiveFind(value, 0, BinarySearch.sorted.length - 1, optimize);
} finally {
BinarySearch.sorted = null;
}
} private static int recursiveFind(int value, int start, int end, boolean optimize) {
if (start == end) {
int lastValue = sorted[start]; // start==end
if (value == lastValue)
return start; // start==end
return Integer.MAX_VALUE;
} final int low = start;
final int high = end + 1; // zero indexed, so add one.
final int middle = low + ((high - low) / 2); final int middleValue = sorted[middle];
if (value == middleValue)
return middle;
if (value > middleValue) {
if (optimize && (end - middle) <= SWITCH_TO_BRUTE_FORCE)
return linearSearch(value, middle + 1, end);
return recursiveFind(value, middle + 1, end, optimize);
}
if (optimize && (end - middle) <= SWITCH_TO_BRUTE_FORCE)
return linearSearch(value, start, middle - 1);
return recursiveFind(value, start, middle - 1, optimize);
} private static final int linearSearch(int value, int start, int end) {
for (int i = start; i <= end; i++) {
int iValue = sorted[i];
if (value == iValue)
return i;
}
return Integer.MAX_VALUE;
}
}
Java BinarySearch的更多相关文章
- 配置算法（第4版）的Java编译环境
1. 下载 1.1 JDK http://www.oracle.com/technetwork/java/javase/downloads/index.html选择“Windows x64 180.5 ...
- 算法（第4版）-1.1.1 Java程序的基本结构
开始之前,引用书中的一段话: "学习算法的主要原因是它们能节约非常多的资源,甚至能够让我们完成一些本不可能完成的任务.在某些需要处理上百万个对象的应用程序,设计优良的算法甚至可以将程序运行的 ...
- Java(C#)基础差异-数组
1.填充数组 Java 数组填充替换方法Arrays.fill() 举例如下: import java.util.Arrays; public class FillDemo { public stat ...
- LeetCode 300. Longest Increasing Subsequence最长上升子序列 (C++/Java)
题目: Given an unsorted array of integers, find the length of longest increasing subsequence. Example: ...
- 配置《算法 第四版》的Eclipse开发环境
1. 安装JAVA JAVA网址:http://www.oracle.com/technetwork/java/javase/downloads/index.html 配置环境变量(我把JAVA安装在 ...
- 在Eclipse下配置算法（第四版）运行环境
第一步:配置Eclipse运行环境 Eclipse运行环境配置过程是很简单的,用过Eclipse进行java开发或学习的同学应该都很熟悉这个过程了. 配置过程: (1)系统环境:Windows7 64 ...
- Eclipse直接运行算法第4版例子（重定向和读取指定路径文件）
Eclipse直接运行算法第4版例子(重定向和读取指定路径文件) 版权声明:本文为博主原创文章,遵循CC 4.0 BY-SA版权协议,转载请附上原文出处链接和本声明. 本文链接:https://b ...
- Spark案例分析
一.需求:计算网页访问量前三名 import org.apache.spark.rdd.RDD import org.apache.spark.{SparkConf, SparkContext} /* ...
- JAVA Arrays.binarySearch
转自:http://blog.csdn.net/somebodydie/article/details/8229343 package com.jaky; import java.util.*; pu ...
随机推荐
- [Java]在JAVA中使用Oracle的INSERT ALL语法进行批量插入
Oracle也提供了类似MySQL的批量插入语法,只是稍微别扭些,具体代码如下: package com.hy; import java.sql.Connection; import java.sql ...
- osg 自定义图元
osg::ref_ptr<osg::Geode> OSG_Qt_::createBox() { osg::ref_ptr<osg::Geode> osg_geode = new ...
- SortedMap和TreeMap有什么区别？
SortedMap和TreeMap有什么区别 答: TreeMap的类的源码: public class TreeMap<K,V> extends AbstractMap<K,V ...
- spark简单文件配置
cd /usr/local/spark/spark-2.2.1-bin-hadoop2.7/conf cp slaves.template slaves cp spark-env.sh.templat ...
- Kafka Connect REST Interface
Since Kafka Connect is intended to be run as a service, it also supports a REST API for managing con ...
- Python 函数返回值、作用域
函数返回值 多条return语句: def guess(x): if x > 3: return "> 3" else: return "<= 3&qu ...
- iOS-AVPlayer
MPMoviePlayerController足够强大,几乎不用写几行代码就能完成一个播放器,但是正是由于它的高度封装使得要自定义这个播放 器变得很复杂,甚至是不可能完成.例如有些时候需要自定义播放器 ...
- macpro锁屏后没有进入睡眠
使用命令pmset -g查看,如图,钉钉阻止了屏幕的睡眠,找了下钉钉的配置,也没有发现有关的内容,重启钉钉后问题解决 displaysleep 10 (display sleep prevented ...
- Fakes里的stub和shim的区别
stub常用于虚拟接口.类.方法,无法重写静态方法(stub需要传递到具体调用代码中) shim常用于重写静态方法(在ShimsContext.Create()作用域内,拦截Runtime动态修改方法 ...
- 最新 第一视频java校招面经 （含整理过的面试题大全）
从6月到10月,经过4个月努力和坚持,自己有幸拿到了网易雷火.京东.去哪儿.第一视频等10家互联网公司的校招Offer,因为某些自身原因最终选择了第一视频.6.7月主要是做系统复习.项目复盘.Leet ...