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
- activemq jmx
增加: -Djava.rmi.server.hostname=<IP addr>
- 治理Go模块 服务治理 中台业务 Golang的net.Conn接口，double close
小结: 1.中台业务 前台业务 快车.专车.顺风车,在滴滴这些业务线叫做前台服务,他们有一些共同的特性,都有司机信息,订单的状态,收银,账号等等这些业务逻辑,我们会把专门的业务逻辑集合起来,形成专职的 ...
- Expression: __acrt_first_block == header
File: minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp Line: 996 Expression: __acrt_first_block == ...
- PAT 甲级 1032 Sharing (25 分)(结构体模拟链表,结构体的赋值是深拷贝)
1032 Sharing (25 分) To store English words, one method is to use linked lists and store a word let ...
- C++ - 第一个程序
代码: #include <iostream> using namespace std; int main() { cout << "hello!" < ...
- Java如何获取ResultSet结果中的每一列的数据类型
示例代码片段: ResultSet resultSet = statement.executeQuery(sql); ResultSetMetaData metaData = resultSet.ge ...
- PowerDesigner的安装和数据库创建
PowerDesigner安装方法: http://dev.firnow.com/course/3_program/java/javajs/20090908/174375.html 安装完这2个软件 ...
- 安卓 adb命令
获取包名 aapt d badging C:\Users\600844\Desktop\beijingtoon.apk "package launchable-activity" ...
- WordPress的摘要显示方式
WordPress的后台有摘要显示的栏目,如果没有显示,需要设置一下,如图 在列表页现实的内容的时候,一般是有摘要的显示摘要,没有摘要的截取文章的前一部分文字.代码如下 <?php if(has ...
- SQL Server数据同步交换
一.为了解决数据同步汇聚,数据分发,数据转换,数据维护等需求,TreeSoft将复杂的网状的同步链路变成了星型数据链路. TreeSoft作为中间传输载体负责连接各种数据源,为各种异构数据库之 ...