Hey everyone! I need to change code that was given to me in order to get a faste
ID: 3527815 • Letter: H
Question
Hey everyone! I need to change code that was given to me in order to get a faster compile time. This involves changing all the Lists to Sets (HashSet or TreeSet, whichever runs quicker in this case) and making the code work in the same way. I was able to change a lot of the code, but I can't seem to make it work still... The first part of the code reads two files typed in the Scanner, then creates Lists of the number of words in each and outputs that number, along with the % of words that are the same in either file, then it prints the compile time. So here is the original code, it's pretty short, so I'm guessing it shouldn't be hard, I just don't know what I'm doing wrong:
import java.util.*;
import java.io.*;
public class Vocabulary3 {
public static void main(String[] q) throws FileNotFoundException {
Scanner console = new Scanner(System.in);
giveIntro();
System.out.print("file #1 name? ");
Scanner input1 = new Scanner(new File(console.nextLine())); // moby.txt
System.out.print("file #2 name? ");
Scanner input2 = new Scanner(new File(console.nextLine())); // hamlet.txt
System.out.println();
double time1 = System.currentTimeMillis();
ArrayList<String> list1 = getWords(input1);
ArrayList<String> list2 = getWords(input2);
double time2 = System.currentTimeMillis();
System.out.println("File read time=" + (time2-time1)/1000 + " seconds");
time1 = System.currentTimeMillis();
ArrayList<String> overlap = getOverlap(list1, list2);
reportResults(list1, list2, overlap);
time2 = System.currentTimeMillis();
System.out.println("Process time=" + (time2-time1) + " milliseconds");
}
// post: reads all words from the given Scanner, turning them to lowercase
// and returning a sorted list of the vocabulary of the file
public static ArrayList<String> getWords(Scanner input) {
// ignore all but alphabetic characters and apostrophes
input.useDelimiter("[^a-zA-Z']");
// read all words and sort
ArrayList<String> words = new ArrayList<String>();
while (input.hasNext()) {
String next = input.next().toLowerCase();
words.add(next);
}
Collections.sort(words);
// add unique words to new list and return
ArrayList<String> result = new ArrayList<String>();
if (words.size() > 0) {
result.add(words.get(0));
for (int i = 1; i < words.size(); i++) {
if (!words.get(i).equals(words.get(i - 1))) {
result.add(words.get(i));
}
}
}
return result;
}
// pre : list1 and list2 are sorted and contain no duplicates
// post: constructs and returns an ArrayList containing the words
// in common betweeen list1 and list2
public static ArrayList<String> getOverlap(ArrayList<String> list1,
ArrayList<String> list2) {
ArrayList<String> result = new ArrayList<String>();
int index1 = 0;
int index2 = 0;
while (index1 < list1.size() && index2 < list2.size()) {
int comparison = list1.get(index1).compareTo(list2.get(index2));
if (comparison == 0) {
result.add(list1.get(index1));
index1++;
index2++;
} else if (comparison < 0) {
index1++;
} else { // comparison > 0
index2++;
}
}
return result;
}
// post: explains program to user
public static void giveIntro() {
System.out.println("This program compares the vocabulary of two");
System.out.println("text files, reporting the number of words");
System.out.println("in common and the percent of overlap.");
System.out.println();
}
// pre : overlap contains the words in common between list1 and list2
// post: reports statistics about two word lists and their overlap
public static void reportResults(ArrayList<String> list1,
ArrayList<String> list2,
ArrayList<String> overlap) {
System.out.println("file #1 words = " + list1.size());
System.out.println("file #2 words = " + list2.size());
System.out.println("common words = " + overlap.size());
double percent1 = 100.0 * overlap.size() / list1.size();
double percent2 = 100.0 * overlap.size() / list2.size();
System.out.println("% of file 1 in overlap = " + percent1);
System.out.println("% of file 2 in overlap = " + percent2);
}
}
Explanation / Answer
http://www.java-forums.org/new-java/61380-change-arraylist-hashset-treeset.html