import java.util.Random;
import java.util.concurrent.ForkJoinPool;

/**
 * 
 */

/**
 * In this example, we have an array filled with numbers ranging from 0 to 99.
 * We want to count how many of the numbers are from 0-9, 10-19, etc.... 90-99.
 * @author sbfan
 *
 */
public class HistogramRunner {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// creating our input array, filled with ints from 0-99
		int[] input = new int[99999];
		Random r = new Random();
		for(int i = 0; i < input.length; i++) {
			input[i] = r.nextInt(100);
		}
		
		// now we will try to create a histogram, counting up
		// the # of ints that are 0-9, 10-19, etc.
		int bins = 10; // only 10 possible bins, 0-9, 10-19, ... 90-99.
		int[] results = new int[bins]; 
		
		// sequential way
		for(int i = 0; i < input.length; i++ ) {
			results[input[i] / bins] += 1; // increment count of correct bin
		}
		
		System.out.println("sequential results:");
		
		// Print results
		for(int i = 0; i < results.length; i++) {
			System.out.println("Bin " + i + ": " + results[i]);
		}
		


		// parallel way
		ForkJoinPool fjp = new ForkJoinPool();
		results = fjp.invoke(new Histogram(input, 0, input.length));
		
		System.out.println("parallel results:");	
		

		// Print results
		for(int i = 0; i < results.length; i++) {
			System.out.println("Bin " + i + ": " + results[i]);
		}
		
	}

}