Algs4 BinarySearch.java
* Compilation: javac BinarySearch.java
* Execution: java BinarySearch whitelist.txt < input.txt
* Dependencies: In.java StdIn.java StdOut.java
* Data files: http://algs4.cs.princeton.edu/11model/tinyW.txt
* http://algs4.cs.princeton.edu/11model/tinyT.txt
* http://algs4.cs.princeton.edu/11model/largeW.txt
* http://algs4.cs.princeton.edu/11model/largeT.txt
*
* % java BinarySearch tinyW.txt < tinyT.txt
* 50
* 99
* 13
*
* % java BinarySearch largeW.txt < largeT.txt | more
* 499569
* 984875
* 295754
* 207807
* 140925
* 161828
* [367,966 total values]
*
******************************************************************************/
//package edu.princeton.cs.algs4;
import java.util.Arrays;
import edu.princeton.cs.algs4.StdIn;
import edu.princeton.cs.algs4.StdOut;
import edu.princeton.cs.algs4.In;
/**
* The BinarySearch class provides a static method for binary
* searching for an integer in a sorted array of integers.
*
* The rank operations takes logarithmic time in the worst case.
*
* For additional documentation, see Section 1.1 of
* Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.
*
* @author Robert Sedgewick
* @author Kevin Wayne
*/
public class BinarySearch {
/**
* This class should not be instantiated.
*/
private BinarySearch() { }
/**
* Returns the index of the specified key in the specified array.
*
* @param a the array of integers, must be sorted in ascending order
* @param key the search key
* @return index of key in array a if present; -1 otherwise
*/
public static int indexOf(int[] a, int key) {
int lo = 0;
int hi = a.length - 1;
while (lo <= hi) {
// Key is in a[lo..hi] or not present.
int mid = lo + (hi - lo) / 2;
if (key < a[mid]) hi = mid - 1;
else if (key > a[mid]) lo = mid + 1;
else return mid;
}
return -1;
}
/**
* Returns the index of the specified key in the specified array.
* This function is poorly named because it does not give the rank
* if the array has duplicate keys or if the key is not in the array.
*
* @param key the search key
* @param a the array of integers, must be sorted in ascending order
* @return index of key in array a if present; -1 otherwise
* @deprecated Replaced by {@link #indexOf(int[], int)}.
*/
public static int rank(int key, int[] a) {
return indexOf(a, key);
}
/**
* Reads in a sequence of integers from the whitelist file, specified as
* a command-line argument; reads in integers from standard input;
* prints to standard output those integers that do not appear in the file.
*/
public static void main(String[] args) {
// read the integers from a file
In in = new In(args[0]);
int[] whitelist = in.readAllInts();
// sort the array
Arrays.sort(whitelist);
// read integer key from standard input; print if not in whitelist
while (!StdIn.isEmpty()) {
int key = StdIn.readInt();
if (BinarySearch.indexOf(whitelist, key) == -1)
StdOut.println(key);
}
}
}
/******************************************************************************
* Copyright 2002-2015, Robert Sedgewick and Kevin Wayne.
*
* This file is part of algs4.jar, which accompanies the textbook
*
* Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne,
* Addison-Wesley Professional, 2011, ISBN 0-321-57351-X.
* http://algs4.cs.princeton.edu
*
*
* algs4.jar is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* algs4.jar is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with algs4.jar. If not, see http://www.gnu.org/licenses.
******************************************************************************/
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通过algs4.exe下载来的algs4文件夹，copy过来放在自己的用户名目录下就可以了（algs4文件夹就可以在各个计算机之间重用了）
之后在path里加上
C:\Users\username\algs4\java\bin;C:\Users\username\algs4\bin;
（两条分割线之间的内容就是algs4这本书所要搭载的java环境及其库的配置过程）
algs4文件夹：http://pan.baidu.com/s/1skK7i01
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对于书上正式出现的第一个程序BinarySearch.java
把原代码的package edu.princeton.cs.algs4;注释掉；
加上这三行：
import edu.princeton.cs.algs4.StdIn;
import edu.princeton.cs.algs4.StdOut;
import edu.princeton.cs.algs4.In;
对于以上经验，真的是说多了都是泪啊，
//package edu.princeton.cs.algs4;
import java.util.Arrays;
import edu.princeton.cs.algs4.StdIn;
import edu.princeton.cs.algs4.StdOut;
import edu.princeton.cs.algs4.In;
这几串代码把我都搞得神经衰弱了，对java又不了解，一直相信官方的代码（没看官方的英文说明文档，他应该指明了这个问题，毕竟是大师，那个网站信息量比较大，加上自己英语不行，就没有去官网上找这方面的问题了），其实就是把官方的代码稍加修改就好了，欲哭无泪，几天的光阴就在这几个字符之间消逝了~~~~~
来自http://algs4.cs.princeton.edu/code/的启示
Java Algorithms and Clients
As of August 17, 2015, the "default package" version of algs4.jar has been replaced with a "named package" version. To access the classes in algs4.jar, you will need to use an import statement like the ones below:
Note that the I/O libraries from stdlib.jar are now contained in algs4.jar, so you no longer need stdlib.jar.
在cmd下的重定向截图：
