Notes

  • Boolean - logical statement that can be evaluated to the values true/false
  • EX: if (true) { System.out.println("True code block"); }
  • LOGICAL OPERATORS
    • && - and
    • || - or
    • ! - not
  • Parenthesis matter
  • De Morgan's Law
    • (A ∪ B)' = A' ∩ B'
    • "The complement of the union of the two sets A and B will be equal to the intersection of A' (complement of A) and B' (complement of B)."
    • EX: !((false || !true) || (false && true))

Homework

2009 FRQ 3B 

// assume that getChargingCost() is implemented
public class BatteryCharger
{
    public int getChargingStartTime (int chargeTime)
    {
        int start = 0;

        for (int loop = 0; loop < 25; loop++)
        {
            if (this.getChargingCost(loop, chargeTime) < this.getChargingCost(start, chargeTime))
            {
                start = loop;
            }
        }
        return start;
    }
}
BatteryCharger batteryCharger = new BatteryCharger();
batteryCharger.getChargeStartTime(6);

2017 FRQ 1B 

import java.util.*;

public class Digits
{
    private ArrayList<Integer> digitList;

    public Digits(int num)
    {
        digitList = new ArrayList<Integer>();

        if (num==0)
        {
            digitList.add(new Integer(0));
        }
        while (num > 0)
        {
            digitList.add(0, new Integer(num % 10));
            num /= 10;
        }

    }

    public boolean isStrictlyIncreasing()
    {
        boolean increase = true;

        for (int loop = 0; loop < digitList.size() - 1; loop++)
        {
            if (digitList.get(loop).intValue() >= digitList.get(loop + 1).intValue())
            {
                increase = false;
                return increase;
            }
        }
        return increase;
    }
}
boolean digits1 = new Digits(1356).isStrictlyIncreasing();
boolean digits2 = new Digits(1536).isStrictlyIncreasing();

System.out.printf("%b\n%b", digits1, digits2);

true
false
java.io.PrintStream@73d7d7f8

2019 FRQ 3B 

public class Delimiters
{
    private String openDel;
    private String closeDel;

    public boolean isBalanced(ArrayList<String> delimiters)
    {
        int opencount = 0;
        int closecount = 0;

        for (int loop = 0; loop < delimiters.size(); loop++)
        {
            if (delimiters.get(loop) == openDel)
            {
                opencount++;
            }
            else if (delimiter.get(loop) == closeDel)
            {
                closecount++;
            }

            if (closecount > opencount)
            {
                return false;
            }
        }
        return true;
    }

}