package jp.funnything.competition.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;

import org.apache.commons.io.IOUtils;

public class QuestionReader {
    private final BufferedReader _reader;

    public QuestionReader( final File input ) {
        try {
            _reader = new BufferedReader( new FileReader( input ) );
        } catch ( final FileNotFoundException e ) {
            throw new RuntimeException( e );
        }
    }

    public void close() {
        IOUtils.closeQuietly( _reader );
    }

    public String read() {
        try {
            return _reader.readLine();
        } catch ( final IOException e ) {
            throw new RuntimeException( e );
        }
    }

    public BigDecimal[] readBigDecimals() {
        return readBigDecimals( " " );
    }

    public BigDecimal[] readBigDecimals( final String separator ) {
        final String[] tokens = readTokens( separator );

        final BigDecimal[] values = new BigDecimal[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = new BigDecimal( tokens[ index ] );
        }

        return values;
    }

    public BigInteger[] readBigInts() {
        return readBigInts( " " );
    }

    public BigInteger[] readBigInts( final String separator ) {
        final String[] tokens = readTokens( separator );

        final BigInteger[] values = new BigInteger[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = new BigInteger( tokens[ index ] );
        }

        return values;
    }

    public int readInt() {
        final int[] values = readInts();

        if ( values.length != 1 ) {
            throw new IllegalStateException( "Try to read single interger, but the line contains zero or multiple values" );
        }

        return values[ 0 ];
    }

    public int[] readInts() {
        return readInts( " " );
    }

    public int[] readInts( final String separator ) {
        final String[] tokens = readTokens( separator );

        final int[] values = new int[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = Integer.parseInt( tokens[ index ] );
        }

        return values;
    }

    public long readLong() {
        final long[] values = readLongs();

        if ( values.length != 1 ) {
            throw new IllegalStateException( "Try to read single interger, but the line contains zero or multiple values" );
        }

        return values[ 0 ];
    }

    public long[] readLongs() {
        return readLongs( " " );
    }

    public long[] readLongs( final String separator ) {
        final String[] tokens = readTokens( separator );

        final long[] values = new long[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = Long.parseLong( tokens[ index ] );
        }

        return values;
    }

    public String[] readTokens() {
        return readTokens( " " );
    }

    public String[] readTokens( final String separator ) {
        return read().split( separator );
    }
}

package fixjava;

import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * A work queue that allows the work queue to continue to increase in size if it is discovered that subdivision of work is
 * necessary. Call hasIdleWorkers() to see if there are idle workers, and have the worker subdivide their work further by calling
 * enqueueWork().
 */
public class ParallelWorkQueueDynamic {

	private int numThreads;
	private ExecutorService threadPool;
	private CompletionService<Void> completionService;

	private int numWorkUnitsEnqueued = 0;
	private Object lock = new Object();

	public ParallelWorkQueueDynamic(int numThreads) {
		this.numThreads = numThreads;
		threadPool = Executors.newFixedThreadPool(numThreads);
		completionService = new ExecutorCompletionService<Void>(threadPool);
	}

	/**
	 * Enqueue work. Called by the main thread to start processing, and can also be called by workers to subdivide their work.
	 */
	public void enqueueWork(Callable<Void> workUnit) {
		synchronized (lock) {
			numWorkUnitsEnqueued++;
		}
		completionService.submit(workUnit);
	}

	/**
	 * Test if there are any idle workers. Should only be called from within a worker so that the total number of workers is greater
	 * than zero (to avoid a race).
	 */
	public boolean hasIdleWorkers() {
		return numWorkUnitsEnqueued < numThreads;
	}

	/**
	 * Wait for all work submitted by workers to be completed. Throws IllegalArgumentException if any of the worker threads throw an
	 * exception (this causes an ExecutionException).
	 */
	public void waitForAllWorkersToQuit() {
		try {
			while (numWorkUnitsEnqueued > 0) {
				// .take() waits for completion of next task and returns a Future for it
				completionService.take().get();
				synchronized (lock) {
					numWorkUnitsEnqueued--;
				}
			}
		} catch (InterruptedException e) {
			e.printStackTrace();
			throw new IllegalArgumentException("waitForAllWorkersToQuit() failed with " + e.getMessage(), e);
		} catch (ExecutionException e) {
			e.printStackTrace();
			throw new IllegalArgumentException("waitForAllWorkersToQuit() failed with " + e.getMessage(), e);
		}
	}

	public void shutdown() {
		threadPool.shutdown();
	}
}
