public static void main(String[] args) {
// Default values
int numInputFiles = 2;
String tempDirectory = System.getProperty("user.dir");
String outputDirectory = "";
String inputDirectory = "";
// Readers
BufferedReader inputReader = null;
BufferedReader[] bufferedReaders = null;
FileReader fr = null;
// Writers
BufferedWriter[] bufferedWriters = null;
int currentFile = 0;
// Files for input/output of runs
File[] inputs = null;
File[] outputs = null;
int comparisonsCount = 0;
int runsCount = 0;
int passesCount = 0;
try {
System.out.println();
// Get the arguments if they exist
if (args.length == 1) {
inputDirectory = args[args.length - 1];
} else if (args.length > 1) {
for (int i = 0; i < args.length; i++) {
if (args[i].equals("-k")) {
if (isNumeric(args[i + 1])) {
// Check for any value above 2 (the default)
if (Integer.parseInt(args[i + 1]) > 2) {
// Get the number of input files
numInputFiles = Integer.parseInt(args[i + 1]);
}
}
} else if (args[i].equals("-t")) {
tempDirectory = args[i + 1];
} else if (args[i].equals("-o")) {
outputDirectory = args[i + 1];
}
}
System.out.println(args[args.length - 2]);
if (!args[args.length - 2].contains("-")) {
inputDirectory = args[args.length - 1];
}
}
System.out.println("Number of input files:" + numInputFiles);
System.out.println("Temporary directory:" + tempDirectory);
System.out.println("Output directory:" + outputDirectory);
System.out.println("Input directory:" + inputDirectory);
System.out.println();
// Create array of temp Files
inputs = new File[numInputFiles];
// Need the same number of writers as input files
bufferedWriters = new BufferedWriter[numInputFiles];
bufferedReaders = new BufferedReader[numInputFiles];
String filePrefix = "tmp_";
// Create the array of input files
for (int i = 0; i < numInputFiles; i++) {
inputs[i] = new File(tempDirectory + "/" + filePrefix + i + ".txt");
inputs[i].createNewFile();
bufferedWriters[i] = new BufferedWriter(new FileWriter(inputs[i].getAbsoluteFile()));
}
inputReader = new BufferedReader(new FileReader(inputDirectory));
// Start creating the runs
String[] run = new String[15];
for (int i = 0; i < 15; i++) {
// Put the first 15 elements from raw data into the array
if (inputReader.ready()) run[i] = inputReader.readLine();
}
// Build the priority queue by passing it the unsorted array
MinHeap heap = new MinHeap(run);
System.out.print("initial unsorted heap:");
heap.traverse();
heap.heapify();
System.out.print("sorted heap:");
heap.traverse();
// Count on the temp file which we are writing to
int tempWriteCounter = 0;
String line = "";
boolean endOfStream = false;
// While the heap is not empty
while (!heap.isEmpty() && !endOfStream) {
// Write minimum to output
String min = heap.remove();
System.out.println("wrote: " + min + " to output");
bufferedWriters[tempWriteCounter].write(min);
bufferedWriters[tempWriteCounter].newLine();
// Make sure reader is ready
if (inputReader.ready() && !endOfStream) {
// If there are more elements to read in
// if((line = inputReader.readLine()) != null){
line = inputReader.readLine();
System.out.println("read in: " + line);
// If the new input is smaller than the last element output to file,
// add it to the dead space of the heap using .append(line);
if (MinHeap.precedesValue(line, min)) {
System.out.println(line + " is less than " + min + ", so append " + line);
heap.append(line);
} else {
System.out.println(line + " is greater than " + min + ", so insert " + line);
heap.insert(line);
}
} else {
endOfStream = true;
System.out.println("Reached end of stream-1");
}
heap.traverse();
// If the heap is empty AND there are more elements to read in,
// fill the heap up, heapify()and write to next temp file
if (heap.isEmpty() && !endOfStream) {
System.out.println("HEAP IS NOW EMPTY... begin next run");
// Find out how many new elements need to be added to fill the heap
int numElements = heap.getEmptyCells();
// Create the array of appropriate size
String[] remaining = new String[numElements];
System.out.println("number of new elements needed: " + numElements);
// Index for the new array
int i = 0;
// While there are more elements to read in AND there are still empty spaces in the heap
while (!endOfStream && i < numElements) {
if (inputReader.ready()) {
line = inputReader.readLine();
System.out.println("read in: " + line);
remaining[i] = line;
} else {
endOfStream = true;
System.out.println("Reached end of stream-2");
}
}
// Fill the empty spaces in the heap
heap.fill(remaining);
heap.heapify();
heap.traverse();
// Proceed to the next temp file
tempWriteCounter++;
}
}
inputReader.close();
// Close the writers
for (int i = 0; i < bufferedWriters.length; i++) {
bufferedWriters[i].close();
// bufferedReaders[i].close();
}
System.out.println();
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
// System.out.println();
// Priority Queue
MinHeap minHeap = new MinHeap();
// Stuff to show that insert() works
/*
minHeap.insert("d");
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.insert("b");
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.insert("e");
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.insert("c");
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.insert("a");
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.remove();
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.remove();
System.out.println();
minHeap.traverse();
System.out.println();
minHeap.remove();
System.out.println();
minHeap.traverse();
System.out.println();
*/
// Stuff to show that heapify() works
/*
String[] array = new String[14];
array[0] = "n";
array[1] = "i";
array[2] = "e";
array[3] = "l";
array[4] = "b";
array[5] = "h";
array[6] = "d";
array[7] = "a";
array[8] = "k";
array[9] = "o";
array[10] = "j";
array[11] = "c";
array[12] = "f";
array[13] = "g";
minHeap = new MinHeap(array);
minHeap.traverse();
System.out.println();
minHeap.heapify();
minHeap.traverse();
*/
System.out.println();
}
