Not able to write complete output to file

[Ashwin Rao]

Hi,
I'm trying to find out the minimum scalar product of a given two vectors. I've succeeded in my attempt to find out the minimum scalar product. I found the question here. I'm trying to solve the small input. My program calculates the minimum scalar product for all 1000 cases but is only writing 845 of them to the file. I don't understand what's the problem. I think it may have something to do with FileWriter. Any help is much appreciated.
My code is given below:

import java.io.*;
import java.util.*;

class MinimumScalarProduct {
	public static void main(String[] args) {
		try
		{
			File inputFile = new File("A-small-practice.in");
			FileReader reader = new FileReader(inputFile);
			BufferedReader bReader = new BufferedReader(reader);
			FileWriter writer = new FileWriter("Output.txt");
			int numberOfCases = Integer.parseInt(bReader.readLine());
			StringBuilder output= new StringBuilder();
			for(int i = 0; i < numberOfCases; i++) {
				int lengthOfTheTwoArrays = Integer.parseInt(bReader.readLine());
				ArrayList<Integer> arrayOne = new ArrayList<Integer>();
				String arrayOneOfString = bReader.readLine();
				stringToArrayList(arrayOneOfString,arrayOne);
				ArrayList<Integer> arrayTwo = new ArrayList<Integer>();
				String arrayTwoOfString = bReader.readLine();
				stringToArrayList(arrayTwoOfString,arrayTwo);
				Collections.sort(arrayOne);
				Collections.sort(arrayTwo);
				int count = 0;
				count = arrayTwo.size() - 1;
				long scalarProduct = 0;
				for(int j = 0; j < arrayOne.size(); j++) {
					scalarProduct += arrayOne.get(j) * arrayTwo.get(count--);
				}

                 writer.write("Case #"+(i + 1)+": "+scalarProduct+"\n");

			}

			

		}

		catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void stringToArrayList(String array, ArrayList<Integer> integerArray) {
		String [] individualStrings = array.split(" ");
		for (String string : individualStrings) {
			integerArray.add(Integer.parseInt(string));
		}
	}
}

[Ashwin Rao]

I had forgotten to close the writer!!
After I added writer.close() I got the output! Sorry for the trouble!

[Liutauras Vilda]

Hi,

You still can improve your program, by:

1. Avoiding explicit imports on lines 1, 2.
2. By shortening your "main" method to a 1 or 2 lines in total.
3. By decomposing your code to a methods, which takes care of a single tasks.

[Campbell Ritchie]

How did you close the writer? Did you read the documentation for close() and did this explain your problem?

[Ashwin Rao]

Closing the writer first flushes it and then closes it. So I guess it would have worked if I had just flushed it.

[Campbell Ritchie]

Yes and no. You would have had the file written had you simply called flush() but failing to close the writer can cause a resource leak.