// Example 134 from page 107

//

import java.util.*;

// The HashSet is 3 to 9 times faster than Arrays.binarySearch, even

// for this list of strings of only 52 elements:

class Example134 {

final static String[] keywordarray =

{ "abstract", "assert", "boolean", "break", "byte", "case", "catch",

"char", "class", "const", "continue", "default", "do", "double", "else",

"enum", "extends", "false", "final", "finally", "float", "for", "goto",

"if", "implements", "import", "instanceof", "int", "interface", "long",

"native", "new", "null", "package", "private", "protected", "public",

"return", "short", "static", "strictfp", "super", "switch",

"synchronized", "this", "throw", "throws", "transient", "true",

"try", "void", "volatile", "while" };

final static Set<String> keywords

= new HashSet<String>(Arrays.asList(keywordarray));

static boolean isKeyword1(String id)

{ return keywords.contains(id); }

static boolean isKeyword2(String id)

{ return Arrays.binarySearch(keywordarray, id) >= 0; }

public static void main(String[] args) {

if (args.length != 2)

System.out.println("Usage: java Example134 <iterations> <word>");

else {

final int count = Integer.parseInt(args[0]);

final String id = args[1];

for (int i=0; i<keywordarray.length; i++)

if (isKeyword1(keywordarray[i]) != isKeyword2(keywordarray[i]))

System.out.println("Error at i = " + i);

if (isKeyword1(id) != isKeyword2(id))

System.out.println("Error at id = " + id);

System.out.print("HashSet.contains ");

Timer t1 = new Timer();

for (int i=0; i<count; i++)

isKeyword1(id);

System.out.println(t1.check());

System.out.print("Arrays.binarySearch ");

Timer t2 = new Timer();

for (int i=0; i<count; i++)

isKeyword2(id);

System.out.println(t2.check());

}

}

// Simple timer, measuring wall-clock (elapsed) time in seconds

private final static class Timer {

private long start;

public Timer() {

start = System.nanoTime();

}

public double check() {

return (System.nanoTime() - start)/1e9;

}

}

}