APCS Written Test Practice 2014

APCS-Test-Practice-2014.java

// 1a
public static String scrambleWord(String word) {
	String newWord = "";
	for(int i = 0; i < word.length - 1; i++) {
		if(word.charAt(i) == 'A' && word.charAt(i + 1) != 'A') {
			newWord += word.charAt(i + 1) + word.charAt(i);
			i++;
		} else {
			newWord += word.charAt(i);
		}
	}
	newWord += word.charAt(word.length - 1); // important! loop only goes to length - 1 to avoid
						 // an ArrayOutOfBoundsException in the if statement
	return newWord;
}

// 1b
public static void scrambleOrRemove(List<String> wordList) {
	for(int i = 0; i < wordList.size(); i++) {
		String scrambled = scrambleWord(wordList.get(i));
		if(wordList.get(i).equals(scrambled)) {
			wordList.remove(i);
			i--;
		} else {
			wordList.set(i, scrambled);
		}
	}
}

// 2a
// skipped because we didn't do GridWorld

// 2b
// skipped because we didn't do GridWorld

// 3a
public SeatingChart(List<Student> studentList, int rows, int cols) {
	seats = new Student[rows][cols];
	int studentIndex = 0; // the next student to assign a seat to
	for(int c = 0; c < seats[0].length; c++) {
		for(int r = 0; r < seats.length; r++) {
			if(studentIndex < studentList.size()) {
				seats[r][c] = studentList.get(studentIndex);
				studentIndex++; // don't forget this!
			}
			// we don't need an else, as objects have a default value of null
		}
	}
}

// 3b
public int removeAbsentStudents(int allowedAbsences) {
	int studentsRemoved = 0;
	for(int c = 0; c < seats[0].length; c++) {
		for(int r = 0; r < seats.length; r++) {
			if(seats[r][c] != null && seats[r][c].getAbsenceCount() > allowedAbsences) { // I forgot the null check,
												      // which is quite important
				seats[r][c] = null;
				studentsRemoved++;
			}
		}
	}
	return studentsRemoved;
}

// 4
public class Trio implements MenuItem {
	private Sandwich mySandwich;
	private Salad mySalad;
	private Drink myDrink;
	
	public Trio(Sandwich sand, Salad sal, Drink dr) {
		mySandwich = sand;
		mySalad = sal;
		myDrink = dr;
	}
	
	public String getName() {
		return mySandwich.getName() + "/" + mySalad.getName() + "/" + myDrink.getName() + " Trio";
	}
	
	public double getPrice() {
		double sandwichPrice = mySandwich.getPrice();
		double saladPrice = mySalad.getPrice();
		double drinkPrice = myDrink.getPrice();
		
		// This will work, but I'm not supposed to do it apparently... :(
		//return ((sandwichPrice >= saladPrice && saladPrice >= drinkPrice) ? (sandwichPrice + saladPrice) :
		//		(saladPrice >= drinkPrice && drinkPrice >= sandwichPrice) ? (saladPrice + drinkPrice) :
		//		(drinkPrice + sandwichPrice));
		
		// This is much more boring than ternary. :(
		if(sandwichPrice >= saladPrice && saladPrice >= drinkPrice)
			return (sandwichPrice + saladPrice);
		else if(saladPrice >= drinkPrice && drinkPrice >= sandwichPrice)
			return (saladPrice + drinkPrice);
		else
			return (drinkPrice + sandwichPrice);
	}
	
	// the whole getPrice method as one line:
	//public double getPrice() { return ((mySandwich.getPrice() >= mySalad.getPrice() && mySalad.getPrice() >= myDrink.getPrice()) ? (mySandwich.getPrice() + mySalad.getPrice()) : (mySalad.getPrice() >= myDrink.getPrice() && myDrink.getPrice() >= mySandwich.getPrice()) ? (mySalad.getPrice() + myDrink.getPrice()) : (myDrink.getPrice() + mySandwich.getPrice())); }
}