Exam 2 Review Proposed Student Solutions (Problem 6)

ArrayProcessor.java

package exam2Review;

public class ArrayProcessor 
{ 
	// Processes values in an array using the given Processor 
	public static double runProcessor(double[] arr, Processor p) 
	{ 
		for (int i = 0; i < arr.length; ++i) 
		{ 
			p.process(arr[i]); 
		} 
		return p.getResult(); 
	} 

}

MaxProcessor.java

package exam2Review;

public class MaxProcessor implements Processor
{
	private double maxValue;
	
	public MaxProcessor(){
		maxValue = Double.NEGATIVE_INFINITY;
	}
	
	public void process(double value){
		maxValue = Math.max(maxValue, value);
	}
	
	public double getResult(){
		return maxValue;
	}
}

Problem6Tester.java

package exam2Review;


public class Problem6Tester {

	public static void main(String[] args) {
		// Data
		double[] arrayOfDoubles = {83.82072588, 79.06909553, -19.32759285, 62.01153403, -20.52662657, 57.89045724, 94.66377192, 80.0163969, 30.87834387, 49.25945775, 24.19614326, -24.64202999, 13.73394567, 57.79859793, 47.56516579, 62.50330916, 96.37163676, 81.23606573, -25.45816438, -6.283612409, 57.30437988, 21.64743784, 55.48922371, 95.63340087, -12.74511854, 44.5431559, 7.172229891};
		
		// check maxProcesser
		double actualMax = 96.3716367622209;
		
		Processor maxFinder = new MaxProcessor();
		double max = ArrayProcessor.runProcessor(arrayOfDoubles, maxFinder);
		
		if (Math.abs(actualMax-max) < 1e-8){
			System.out.println("The correct max was found, " + max);
		}
		else {
			System.out.println("failed to find correct max, " + actualMax + ".  Instead this is what was found: " + max + "\n");
		}
		
		
		// Check range counter
		double minOfRange = -20.0;
		double maxOfRange = 32.0;
		double actualCountInRange = 8;
		
		Processor rangeFinder = new RangeCounter(minOfRange, maxOfRange);
		double countInRange = ArrayProcessor.runProcessor(arrayOfDoubles, rangeFinder);
		
		if (Math.abs(countInRange - actualCountInRange) < 1e-8)
		{
			System.out.println("The correct count within the range of ("
					+ minOfRange + ", " + maxOfRange + ") was found. Count = "
					+ (int)actualCountInRange);
		}
		else {
			System.out.println("The correct count was NOT found in range of ("	
		                       + minOfRange + ", " + maxOfRange + 
		                       ").  correct count = " + (int)actualCountInRange);
		}
		

	}

}

Processor.java

/**
 * 
 */
package exam2Review;

/**
 * @author Jason Nicholson
 *
 */
public interface Processor {
	public void process(double value);
	public double getResult();
}

RangeCounter.java

package exam2Review;

public class RangeCounter implements Processor{
	
	double minRange;
	double maxRange;
	int count;
	
	public RangeCounter(double minRange, double maxRange){
		this.minRange = minRange;
		this.maxRange = maxRange;
		this.count = 0;
	}
	
	public void process(double value) {
		// I am considering the bounds as noninclusive.
		if (value > this.minRange && value < this.maxRange)
		{
			count++;
		}
	}
	
	public double getResult(){
		// cast the count to a double and return
		return (double)count;
	}
	
}

Problem6Tester.java is the file that you should run once you have added all these files to your project.