So i am currently workin on my homework and cant seem to get the .csv file into a 2D-array. The thing is that we have to use the Scanner and the .split() method, no workarounds. currently it seems to only load second to last line into the whole array.
The .csv file looks like this:
8;2;0;1;4;5;7;6;9
9;0;4;2;6;7;3;0;8
7;6;0;3;8;9;4;5;2
1;0;0;7;9;0;5;4;0
5;0;6;4;2;0;0;3;7
0;0;9;5;3;6;8;2;1
3;9;7;6;1;4;0;8;0
0;0;8;9;5;2;0;7;3
2;0;5;0;0;3;6;0;4
so the problem would be in the while-loop in "readArrayFromFile", everything else has been predetermined.
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class array2D{
private static int[][] readArrayFromFile(String filename) {
int[][] array = new int[9][9];
try {
Scanner myFileReader = new Scanner(new File(filename));
while (myFileReader.hasNextLine()) {
String line = myFileReader.nextLine();
String[] tokens = line.split(";");
for (int i = 0; i < tokens.length; i++) {
for (int j = 0; j < tokens.length; j++) {
if (myFileReader.hasNext()) {
array[i][j] = Integer.parseInt(tokens[j]);
}
}
}
}
} catch (FileNotFoundException e) {
System.out.println(e.getMessage());
}
return array;
}
private static void printArray(int[][] inputArray) {
for (int y = 0; y < inputArray.length; y++) {
for (int x = 0; x < inputArray[y].length; x++) {
System.out.print(inputArray[y][x] + "\t");
}
System.out.println();
}
System.out.println();
}
public static void main(String[] args) {
String filename = "./src/sudoku1.csv";
int[][] sudokuField = readArrayFromFile(filename);
printArray(sudokuField);
}
}
You don't need 2 loops in while loop, here is the solution.
public class array2D
{
private static int[][] readArrayFromFile(String filename)
{
int[][] array = new int[9][9];
try
{
Scanner myFileReader = new Scanner(new File(filename));
int i = 0;
while (myFileReader.hasNextLine())
{
String line = myFileReader.nextLine();
String[] tokens = line.split(";");
for (int j = 0; j < tokens.length; j++)
{
array[i][j] = Integer.parseInt(tokens[j]);
}
i++;
}
}
catch (FileNotFoundException e)
{
System.out.println(e.getMessage());
}
return array;
}
private static void printArray(int[][] inputArray)
{
for (int y = 0; y < inputArray.length; y++)
{
for (int x = 0; x < inputArray[y].length; x++)
{
System.out.print(inputArray[y][x] + "\t");
}
System.out.println();
}
System.out.println();
}
public static void main(String[] args)
{
String filename = "./src/test.csv";
int[][] sudokuField = readArrayFromFile(filename);
printArray(sudokuField);
}
}
From my understanding, your problem is with the nested for loops. Your current code is going to fill the whole 2d array with the last line. My fix would be to place a counter inside the while loop, get rid of one of the for loops, and then it should work. I hope that makes sense
Don't be afraid of using more than one Scanner at once:
private static int[][] readArrayFromFile(String filename) {
int[][] array = new int[9][9];
int rowNum = 0;
try (Scanner myFileReader = new Scanner(new File(filename))) {
while (myFileReader.hasNextLine()) {
String line = myFileReader.nextLine();
Scanner sRow = new Scanner(line);
sRow.useDelimiter(";");
int colNum = 0;
while (sRow.hasNextInt()) {
array[rowNum][colNum++] = sRow.nextInt();
}
rowNum++;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return array;
}
Related
I have to sort strings in an array for a school project. Our teacher won't allow us to use array,sort().
i have to use 2 sort methods but they aren't working too well.
The first one returns double of each value. ie John, jack, adam, tom will return adam,adam,jack,jack,john,john,tom,tom.
public static void sort() {
inputFileNames();//inputs list of names from a file.
for (int i = 0; i < size - 1; i++) {
for (int j = i + 1; j < size; j++) {
if (stArr[i].compareTo(stArr[j])>0) {
temp = stArr[i];
stArr[i] = stArr[j];
stArr[j] = temp;
}
}
}
display("The names are: ");// method to display array
System.out.println("");
}
the second sort doesn' run:
public static void bubbleSort() {
inputFileNames();
for (int i = size - 1; i >= 0; i--) {
for (int j = 0; j <= i; j++) {
if (stArr[j].compareTo(stArr[j+1])>0) {
temp = stArr[j];
stArr[j] = stArr[j + 1];
stArr[j + 1] = temp;
}
}
}
display("The names are: ");
System.out.println("");
}
input and display:
static void display(String heading) {
System.out.println(heading + "\n");
for (int i = 0; i < size; i++) {
System.out.println(stArr[i]);
}
}
static void inputFileNames() {
try {
Scanner scFile = new Scanner(new File("Names.txt"));
while (scFile.hasNext()) {
stArr[size] = scFile.nextLine();
size++;
}
} catch (FileNotFoundException ex) {
System.out.println("File not found.");
}
}
/* package codechef; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
public static void main (String[] args) throws java.lang.Exception
{ Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int i,j;
String[] stArr = new String[n];
for(i=0;i<n;i++)
{
stArr[i]=sc.next();
// System.out.println(stArr[i]);
}
//inputs list of names from a file.
for (i = 0; i < n ; i++) {
for (j = i+1 ; j < n; j++) {
if (stArr[i].compareTo(stArr[j])>0)
{
String temp = stArr[i];
stArr[i] = stArr[j];
stArr[j] = temp;
// System.out.println(stArr[i]);
// System.out.println(stArr[j]);
}
}
}
for(i=0;i<n;i++)
{
System.out.println(stArr[i]);
}
// your code goes here
}
}
This Is the answer for first code. I am not good in file handling so you have to use your input method. I know Scanner thats why i have used here.
In Your Second Example Your j loop is wrong it should be for ( j = 0; j <= i-1; j++). And Please Mark It as answer if your problem is solved
I am trying to create a dictionary out of a .txt file.The problem I think is in my addToDict method. I am trying to resize th array when its full because I am reading from a text file of unknown size but I can only use arrays. I get an out of bounds exception when I am printing the array. I have no idea whats wrong and I have been working on the project for days now. I am also having trouble with my else statement in my addToDict method. It is also and out of bounds exception
import java.io.*;
import java.util.Scanner;
import java.util.regex.*;
public class BuildDict {
static String dict[] = new String[20];
static int index = 0;
public static void main(String args[]) {
readIn();
}
public static void readIn() {
File inFile = new File("alice.txt");
try {
Scanner scan = new Scanner(inFile);
while (scan.hasNext()) {
String word = scan.next();
if (!Character.isUpperCase(word.charAt(0))) {
checkRegex(word);
}
}
scan.close();
} catch (IOException e) {
System.out.println("Error");
}
}
public static void addToDict(String word) {
if (index == dict.length) {
String newAr[] = new String[index * 2];
for (int i = 0; i < index; i++) {
newAr[i] = dict[i];
}
newAr[index] = word;
index++;
dict = newAr;
for (int j = 0; j < index; j++) {
System.out.println(newAr[j]);
}
} else {
dict[index] = word;
index++;
}
}
public static void checkRegex(String word) {
String regex = ("[^A-Za-z]");
Pattern check = Pattern.compile(regex);
Matcher regexMatcher = check.matcher(word);
if (!regexMatcher.find()) {
addToDict(word);
}
}
}
You haven't assigned the new array to dict.
if (index == dict.length) {
for (int i = 0; i < index; i++) {
newAr[i] = dict[i];
}
newAr[index] = word;
index++;
for (int j = 0; j < index; j++) {
System.out.println(newAr[j]);
}
// Assign dict to the new array.
dict = newAr;
} else {
dict[index] = word;
index++;
}
The value of index is 0 when the following statement is executed.
String newAr[] = new String[index*2];
Try revisiting your logic. index should be given a positive value before this method is called. That's why you are getting OutOfBounds.
EDIT: Did you mean to write index+2?
You have
static int index = 0;
You need to change the value of this variable, based on your file, otherwise you will always have an error in this line
String newAr[] = new String[index*2];
Instead of using a array use a arraylist for when you don't know the size of your array. It will save you a lot of trouble. I find they are much easier to work with in general then normal arrays.
ArrayList<String> dict = new ArrayList<>();
dict.add(word);
//displaying values
for( int i = 0; i < dict.size(); i++ ){
System.out.println(dict.get(i));
}
Im trying to write a program with three instance methods, but I cant seem to get it right. My method wordCount returns the number of lines in the file. Not the number of words as its supposed to.
Im just lost in the method mostFrequentWords..
Hope someone can help me out
package opgaver;
import java.util.*;
import java.io.*;
public class TextAnalysis14 {
Scanner file;
int CountWords = 0;
boolean Contains = true;
String[] words;
String[] MFwords;
public TextAnalysis14(String sourceFileName, int maxNoOfWords) {
String wordline;
words = new String[maxNoOfWords];
String[] line;
try {
file = new Scanner(new File(sourceFileName));
} catch (FileNotFoundException e) {
file = new Scanner("");
}
while (file.hasNext()) {
wordline = file.next();
line = wordline.split("[^a-zA -Z]+");
for (int i = 0; i < line.length; i++) {
if (!line[i].equals(" ")) {
words[CountWords] = line[i];
CountWords++;
}
}
}
if (words[CountWords] == (null)) {
for (int i = CountWords; i < maxNoOfWords; i++) {
words[i] = ("empty");
}
}
}
public int wordCount() {
return CountWords;
}
public boolean contains(String word) {
for (int i = 0; i < words.length; i++) {
if (words[i].contains(word)) {
return Contains;
}
}
return false;
}
public String[] mostFrequentWords() {
Arrays.sort(words);
return MFwords;
}
}
Because of my noob status I cannot make a comment but it looks like you have a space in your regex between A and -Z.
try with this.
public static void main(String[] args) {
String str = "this is a space String"; // read all lines in a file
String[] splited = str.split(" ");
List<String> list = new ArrayList<String>();
for(int i = 0;i < splited.length; i++){
if(splited[i].length() > 0){
list.add(splited[i]);
}
}
System.out.println(list.size());
}
by calling wordline = file.next(); you are not reading lines.
In TextAnalysis14 change your condition to file.hasNextLine() and read lines with file.nextLine()
while (file.hasNextLine()) {
wordline = file.nextLine();
....
}
You can try something like that using Java 8:
Stream<String> lines = Files.lines(Paths.get("c:/", "file.txt"));
in wordCount = lines.mapToInt(s -> s.split(' ').length()).sum();
This function just cound a words count in file.
This is the text file:
1,2,8,4,5,6,7,7,
3,4,5,6,7,8,
5,6,7,8,9,9,
1,2,3,4,5,8,9,0
After ignoring the 1st column:
2,8,4,5,6,7,7,
4,5,6,7,8,
6,7,8,9,9,
2,3,4,5,8,9,0
I want to sort the array in descending order but I can't get it to work. This is the code that I have done so far:
Scanner scanner = new Scanner(new File("test.txt"));
int row = 0;
int col = 0;
while (scanner.hasNextLine())
{
String currentline = scanner.nextLine();
row++;
String[] items = currentline.split(",");
int[] intitems = new int[items.length];
for (int i = 1; i < items.length; i++)
{
intitems[i] = Integer.parseInt(items[i]);
System.out.print(intitems[i] + " ");
int temp = 0;
for (int j = 2; j < (items.length - i); j++)
{
temp = intitems[j - 1];
intitems[j - 1] = intitems[j];
intitems[j] = temp;
}
col = i;
}
col++;
System.out.println();
System.out.println("After sort: " + intitems);
System.out.println();
}
System.out.println("Row: " +row);
No need to complicate things:
for (int i = 1; i < items.length; i++) {
intitems[i - 1] = Integer.parseInt(items[i]);
}
Arrays.sort(intitems); // Ascending
Arrays.sort(intitems, Collections.reverseOrder()); // Descending
But if you really want to use a loop to sort the array (bubblesort) you need to compare the items you switch:
for (int i = 0; i < intitems.length - 1; i++) {
for(int j = i + 1; j < intitems.length; j++) {
if (intitems[i] > intitems[j]) {
int temp = intitems[j];
intitems[j] = intitems[i];
intitems[i] = temp;
}
}
}
If you want it sorted in descending order then just change the greater than (>) comparison to a lesser than (<) comparison:
if (intitems[i] < intitems[j]) {
private static void sortInDescending(int[] arrayObj)
{
int n = arrayObj.length;
int temp = 0;
for(int i=0; i < n; i++)
{
for(int j=1; j < (n-i); j++)
{
if(arrayObj[j-1] < arrayObj[j])
{
temp = arrayObj[j-1];
arrayObj[j-1] = arrayObj[j];
arrayObj[j] = temp;
}
}
}
}
Call method
sortInDescending(arrayinput);
You can use the Arrays.sort() with a custom comparator to make it descending.
String[] items = currentLine.split(",");
Integer[] intItems = new Integer[items.length];
for(int i=0; i<intItems.length; ++i) {
intItems[i] = Integer.parseInt(items[i]);
}
Comparator<Integer> comparator = new Comparator<Integer>() {
#Override
public int compare(Integer left, Integer right) {
return -Integer.compare(left, right);
}
};
Arrays.sort(intItems, comparator);
System.out.println(Arrays.toString(intItems));
}
Or you can sort the array in ascending order and reverse the array.
Arrays.sort(intItems);
Integer[] descending = new Integer[intItems.length];
int length = descending.length;
for(int i=0; i<length; ++i) {
descending[i] = intItems[length - 1 - i];
}
System.out.println(Arrays.toString(descending));
Other answers contain the bubble sort algorithm, where one element is compared to its successor. If the sort condition matches, then they get swapped. A slightly faster solution is insertion sort: in essence, it finds the maximal (minimal) value of the array and puts it to the front. There the implementation could look like this:
static int[] array = {2,8,4,5,6,7,7,};
public static void insertionSort(final int[] array) {
for(int i = 0; i < array.length; i++){
int maxValueIndex = findMaxValue(array, i);
int temp = array[i];
array[i] = array[maxValueIndex];
array[maxValueIndex]=temp;
}
}
private static int findMaxValue(final int[] array, int index) {
int value = Integer.MIN_VALUE;
for (int i = index; i < array.length; i++) {
if (array[i] > value) {
value = array[i];
index = i;
}
}
return index;
}
public static void main(final String[] args){
insertionSort(array);
System.out.println(Arrays.toString(array));
}
There you go :
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class SortTXT {
static File fout;
public static void main(String[] args) {
fout = new File("text.txt");
if (!fout.isFile())
{
System.out.println("text.txt - Parameter is not an existing file");
}
else
{
BufferedReader br = null;
try {
br = new BufferedReader(new InputStreamReader(new FileInputStream(fout)));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
String line = null;
try {
while ((line = br.readLine()) != null) {
if (line.length()>2)
{
line.trim();
// crete an array from the line - seperate by ","
List<String> list = new ArrayList<String>(Arrays.asList(line.split(",")));
// remove the 1st number
list.remove(0);
//sorting the list
Collections.sort(list);
System.out.println();
System.out.println("After sort: ");
// print out the sorted array
for(String temp: list){
System.out.print("," + temp);
}
}
}
} catch (IOException e) {
}
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Hope This Helps :)
Dave.
This question already has an answer here:
Closed 10 years ago.
I run through the entire code. I am able to enter a simple .txt file to search for a word. After it asks for a word, it returns
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -48
at SearchEngine.main(SearchEngine.java:150)
Line 150 is for (int j = 0; j
Any help debugging?
This is basic search engine program that should be able to search a .txt file for any word.
Assignment link: http://cis-linux1.temple.edu/~yates/cis1068/sp12/homeworks/concordance/concordance.html
import java.util.*;
import java.io.*;
public class SearchEngine {
public static int getNumberOfWords (File f) throws FileNotFoundException {
int numWords = 0;
Scanner scan = new Scanner(f);
while (scan.hasNext()) {
numWords++;
scan.next();
}
scan.close();
return numWords;
}
public static void readInWords (File input, String [] x) throws FileNotFoundException {
Scanner scan = new Scanner(input);
int i = 0;
while (scan.hasNext() && i<x.length) {
x[i] = scan.next();
i++;
}
scan.close();
}
public static int getNumOfDistinctWords (File input, String [] x) throws FileNotFoundException {
Scanner scan = new Scanner(input);
int count = 0;
int i = 1;
while (scan.hasNext() && i<x.length) {
if (!x[i].equals(x[i-1])) {
count++;
}
i++;
}
scan.close();
return count;
}
public static void readInDistinctWords (String [] x, String [] y) {
int i = 1;
int k = 0;
while (i<x.length) {
if (!x[i].equals(x[i-1])) {
y[k] = x[i];
k++;
}
i++;
}
}
public static int getNumberOfLines (File input) throws FileNotFoundException {
int numLines = 0;
Scanner scan = new Scanner(input);
while (scan.hasNextLine()) {
numLines++;
scan.nextLine();
}
scan.close();
return numLines;
}
public static void readInLines (File input, String [] x) throws FileNotFoundException {
Scanner scan = new Scanner(input);
int i = 0;
while (scan.hasNextLine() && i<x.length) {
x[i] = scan.nextLine();
i++;
}
scan.close();
}
public static void main(String [] args) {
try {
//gets file name
System.out.println("Enter the name of the text file you wish to search");
Scanner kb = new Scanner(System.in);
String fileName = kb.nextLine();
String TXT = ".txt";
if (!fileName.endsWith(TXT)) {
fileName = fileName.concat(TXT);
}
File input = new File(fileName);
//First part of creating index
System.out.println("Creating vocabArray");
int NUM_WORDS = getNumberOfWords(input);
//System.out.println(NUM_WORDS);
String [] wordArray = new String[NUM_WORDS];
readInWords(input, wordArray);
Arrays.sort(wordArray);
int NUM_DISTINCT_WORDS = getNumOfDistinctWords(input, wordArray);
String [] vocabArray = new String[NUM_DISTINCT_WORDS];
readInDistinctWords(wordArray, vocabArray);
System.out.println("Finished creating vocabArray");
System.out.println("Creating concordanceArray");
int NUM_LINES = getNumberOfLines(input);
String [] concordanceArray = new String[NUM_LINES];
readInLines(input, concordanceArray);
System.out.println("Finished creating concordanceArray");
System.out.println("Creating invertedIndex");
int [][] invertedIndex = new int[NUM_DISTINCT_WORDS][10];
int [] wordCountArray = new int[NUM_DISTINCT_WORDS];
int lineNum = 0;
while (lineNum<concordanceArray.length) {
Scanner scan = new Scanner(concordanceArray[lineNum]);
while (scan.hasNext()) {
int wordPos = Arrays.binarySearch(vocabArray, scan.next());
wordCountArray[wordPos]+=1;
for(int i = 0; i < invertedIndex.length; i++) {
for(int j = 0; j < invertedIndex[i].length; j++) {
if (invertedIndex[i][j] == 0) {
invertedIndex[i][j] = lineNum;
break;
} } }
}
lineNum++;
}
System.out.println("Finished creating invertedIndex");
}
System.out.println("Enter a word to be searched (type quit to exit program)");
Scanner keyboard = new Scanner(System.in);
String searchWord = keyboard.next();
while (!searchWord.equals("quit")) {
int counter = 0;
int wordPos = Arrays.binarySearch(allWordsArray, searchWord);
for (int j = 0; j<invertedIndex[wordPos].length; j++) {
if(invertedIndex[wordPos][j] != 0) {
int number = invertedIndex[wordPos][j];
String printOut = concordanceArray[number];
System.out.print(number);
System.out.print(" :");
System.out.println(printOut);
}
}
}
catch (FileNotFoundException exception) {
System.out.println("File Not Found");
}
} //main
} //class
From what I can see your getNumOfDistinctWords(String[] x) is wrong. This is returning a value of one less than it should be. Here is a modified version of the code:
import java.util.*;
import java.io.*;
public class SearchEngine {
//Counts the number of words in the file
public static int getNumberOfWords (File f) throws FileNotFoundException {
int numWords = 0;
Scanner scan = new Scanner(f);
while (scan.hasNext()) {
numWords++;
scan.next();
}
scan.close();
return numWords;
}
public static void readInWords (File input, String[] x) throws FileNotFoundException {
Scanner scan = new Scanner(input);
int i = 0;
while (scan.hasNext() && i < x.length) {
x[i] = scan.next();
i++;
}
scan.close();
}
public static String[] getNumOfDistinctWords (String[] x) throws FileNotFoundException {
HashSet<String> distinctWords = new HashSet<String>();
for(int i=0; i<x.length; i++){
distinctWords.add(x[i]);
}
String[] distinctWordsArray = new String[distinctWords.size()];
int i = 0;
for(String word : distinctWords){
distinctWordsArray[i] = word;
i++;
}
return distinctWordsArray;
}
public static int getNumberOfLines (File input) throws FileNotFoundException {
int numLines = 0;
Scanner scan = new Scanner(input);
while (scan.hasNextLine()) {
numLines++;
scan.nextLine();
}
scan.close();
return numLines;
}
public static void readInLines (File input, String [] x) throws FileNotFoundException {
Scanner scan = new Scanner(input);
int i = 0;
while (scan.hasNextLine() && i<x.length) {
x[i] = scan.nextLine();
i++;
}
scan.close();
}
public static void main(String [] args) {
try {
//gets file name
System.out.println("Enter the name of the text file you wish to search");
Scanner kb = new Scanner(System.in);
String fileName = kb.nextLine();
String TXT = ".txt";
if (!fileName.endsWith(TXT)) {
fileName = fileName.concat(TXT);
}
File input = new File(fileName);
//First part of creating index
System.out.println("Creating vocabArray");
int NUM_WORDS = getNumberOfWords(input);
//Output the number of words in the file
System.out.println("Number of words is: " + NUM_WORDS);
String[] allWordsArray = new String[NUM_WORDS];
readInWords(input, allWordsArray);
Arrays.sort(allWordsArray);
String[] distinctWordsArray = getNumOfDistinctWords(allWordsArray);
//Output the number of distinct words
System.out.println("Number of distinct words is: " + distinctWordsArray.length);
System.out.println("Finished creating distinctWordsArray");
System.out.println("Creating concordanceArray");
int NUM_LINES = getNumberOfLines(input);
String[] concordanceArray = new String[NUM_LINES];
readInLines(input, concordanceArray);
System.out.println("Finished creating concordanceArray");
System.out.println("Creating invertedIndex");
int [][] invertedIndex = new int[distinctWordsArray.length][10];
int [] wordCountArray = new int[distinctWordsArray.length];
int lineNum = 0;
while (lineNum < concordanceArray.length) {
Scanner scan = new Scanner(concordanceArray[lineNum]);
while (scan.hasNext()) {
//Find the position the word appears on the line, if word not found returns a number less than 0
int wordPos = Arrays.binarySearch(distinctWordsArray, scan.next());
if(wordPos > -1){
wordCountArray[wordPos] += 1;
}
for(int i = 0; i < invertedIndex.length; i++) {
for(int j = 0; j < invertedIndex[i].length; j++) {
if (invertedIndex[i][j] == 0) {
invertedIndex[i][j] = lineNum;
break;
} } }
}
lineNum++;
}
System.out.println("Finished creating invertedIndex");
}
catch (FileNotFoundException exception) {
System.out.println("File Not Found");
}
} //main
} //class
I should also point out the fact that Arrays.binarySearch(distinctWordsArray, scan.next()); will return a number less than 0 if the word is not found on that line. This is why you are getting the Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 as wordCountArray is being referenced at index -1 which of course doesn't exist!
The code after this also looks buggy but I'll let you fix that!!
Without knowing exactly where line 126 is, finding this specific bug is just too much hassle. But I've got some advice for the rest of the code:
int NUM_DISTINCT_WORDS = getNumOfDistinctWords(input, wordArray);
Normally, variables in all-caps are constants that are assigned at compile time. It's a tradition that comes from C days, when it was wonderful to know which "variables" were actually replaced by the preprocessor. But the convention has proven to be useful in other languages, and most programmers would expect NUM_DISTINCT_WORDS to be assigned a specific value at compile time.
This code is simply unreadable:
for(int i = 0; i < invertedIndex.length; i++) {
for(int j = 0; j < invertedIndex[i].length; j++) {
if (invertedIndex[i][j] == 0) {
invertedIndex[i][j] = lineNum;
break;
} } }
A more idiomatic way to show these nested loops is:
for (int i = 0; i < invertedIndex.length; i++) {
for (int j = 0; j < invertedIndex[i].length; j++) {
if (invertedIndex[i][j] == 0) {
invertedIndex[i][j] = lineNum;
break;
}
}
}
Because I use the standard Lindent script to do re-indenting, I get tabs. You don't have to use tabs, but they are convenient to add and delete with a single keystroke, and they are deep enough to be obviously visible even with smallish type faces. You'll find your code far easier to work with if you follow the standard indenting idioms.
The following piece of code is extremely unfortunate:
catch(FileNotFoundException exception) {
System.out.println("File Not Found");
}
It would be better to catch a higher-level exception and include the exception message. You can more easily handle dozens of errors if you catch an exception higher in the hierarchy, and the error messages will be far more informative.
Your main() method performs a lot of detailed work. I think your code would be easier to test, easier to debug, and easier to read, if you break it apart into more methods. Try to get the main() to read practically like a high-level description of your code.
With the line with the bug on it now easily visible, I can spot the problem:
int wordPos = Arrays.binarySearch(vocabArray, scan.next());
wordCountArray[wordPos]+=1;
You've looked up the wordPos in the vocabArray, but modified content in the wordCountArray. Are you sure they are the same size and have the same meanings?