Module: AP Computer Science Section II 2015

interface Solution
{
    /** @return an integer value that ranges from 1 (very acidic)
     * to 14 */
    int getPH();
    /** Set PH to newValue.
     * @param newValue the new PH value */
    void setPH(int newValue);
}

interface MechanicalArm
{
    /** @return the index of the current location of the
     * mechanical arm */
    int getCurrentIndex();
    /** @return true if the mechanical arm is facing right
     * (toward solutions with larger indexes),
     * false if the mechanical arm is facing left
     * (toward solutions with smaller indexes)
     */
    boolean isFacingRight();
    /** Changes the current direction of the mechanical arm */
    void changeDirection();
    /** Moves the mechanical arm forward in its current direction
     * by the number of locations specified.
     * @param numLocs the number of locations to move
     * Precondition: numLocs >= 0.
     */
    void moveForward(int numLocs);
}
class Experiment
{
    /** The mechanical arm used to proсess the solutions */
    private MechanicalArm arm;
    /** The list of solutions */
    private List<Solution> solutions;         

/** Resets the experiment.
     * Postcondition:
     * - The mechanical arm has a current index of 0.
     * - It is facing right.
     */
    public void reset()
    { /* to be implemented in part (a) */         

}
    /** Finds and returns the index of the most acidic solution.
     * @return index the location of the most acidic solution
     * or -1 if there are no acidic solutions
     * Postcondition:
     * - The mechanical arm is facing right.
     * - Its current index is at the most acidic solution, or at
     * 0 if there are no acidic solutions.
     */
    public int mostAcidic()
    { /* to be implemented in part (b) */         

    }
}