http://www.cs.mcgill.ca/~cs202/

1)
a)c >= '0' && c <= '9'
b)i % j == 0 || j % i == 0
c)s1.equals(s2)
d)Math.abs(d1-d2) <= .0001

2)
a)int 0
b)boolean false
c)String Fox
d)boolean false (note that it's always false since dividing by 5 never leaves you with remainder of 7. If you noticed this you got a bonus point, if you proved you knew what modulus meant you got full credit)

3)
a)
2,4,6,8,
b)
F,E,D,C,B,A
c)
xoF n*ilE
d) 
*****
****
***
**
*

4)
a)
public String[] voteByRank(String[] names, int[] ranks) {
	String[] orderedNames = new String[names.length];
	for (int i=0; i < orderedNames.length; i++) {
		orderedNames[ranks[i] - 1] = names[i];
	}
	
	return orderedNames;
}

b)
public String[] voteByIndex(String[] names, int[] indexes) {
	String[] orderedNames = new String[names.length];
	for (int i=0; i < orderedNames.length; i++) {
		orderedNames[i] = names[indexes[i] - 1];
	}
	
	return orderedNames;
}

c)
public int[] convertFromIndexToRank(int[] indexes) {
	int[] ranks = new int[indexes.length];
	for (int i=0; i < ranks.length; i++) {
		ranks[indexes[i] - 1] = i + 1;
	}

	return ranks;
}



5)
Point2D A = new Point2D(1.0,1.0);
Point2D B = new Point2D(2.5,1.5);
Point2D C = new Point2D(2.0, 2.0);

Vector2D AB = new Vector2D(A,B);
Vector2D AC = new Vector2D(A,C);

Vector2D AH = AC.projectOnto(AB);

Point2D H = A.moveBy(AH);

Vector2D HC = new Vector2D(H,C);

System.out.println("The area is " + HC.getLength() * AB.getLength() / 2);

6)
import java.util.Scanner;
public class FlintAnalyser {
	public static void main(String[] args) {
		System.out.println("Please enter the name of the file to be processed");
		Scanner keyboardReader = new Scanner(System.in);
		String filename = keyboardReader.nextLine();

		Scanner scan = new Scanner(new File(filename));

		double height = scan.nextDouble();

		int blades = 0;
		int bladeletts = 0;
		int elongatedFlakes = 0;
		int wideFlakes = 0;
		int numFlints = 0;

		while (	height != 0.0	) {
			double width = scan.nextDouble(); 
			numFlints++;
			if ( height > 2 * width ) {
				blades++;

				if ( height < 5 && width < 1.3) {
					bladeletts++;
				}
			}
			else if ( height > width) {
				elongatedFlakes++;
			}
			else {
				wideFlakes++;
			}

			height = scan.nextDouble();
		}

		System.out.println("Total number of flints processed: " + numFlints);
		System.out.println(" - " + numBlades + " blades (" + blades * 100.0/ numFlints + " %)," + bladeletts + "(" + (bladeletts * 100.0) / (blades) + ") of which are bladeletts.");
		System.out.println(" - " + (elongatedFlakes + wideFlakes) + " flakes (" + ((elongatedFlakes + wideFlakes) * 100.0 / numFlints) + " %), of which " + elongatedFlakes + "(" + (elongatedFlakes  * 100.0 / (elongatedFlakes + wideFlakes)) + "%) are elongated, and " + wideFlakes + "(" + (wideFlakes * 100.0 / (elongatedFlakes + wideFlakes)) + "%) are wide");

	}
}



7)
int numStars = 0;
int numOnes = 0;
for (int i =0; i < number.length(); i++) {
	char digit = number.charAt(i);
	if ( digit != '0' && digit != '1' && digit != '*') {
		System.out.println("Invalid input");
		return;
	}

	if ( digit == '*') {
		numStars++;

		if (numStars > 1) {
			System.out.println("Corrupted beyond repair!");
			return;
		}
	}

	if (digit == '1') {
		numOnes++;
	}
}
if (numOnes % 2 == 0) {
String finalNumber = number.replace('*', '0');
System.out.println(finalNubmer);
}
else {
	System.out.println(number.replace('*', '1'));
}

//Very short answers:
//String finalNumber = numOnes % 2 == 0 ? number.replace('*','0') : number.replace('*', '1');
//String finalNumber = number.replace('*' , '0' + numOnes % 2);