CS 111 - Introduction to Computer Science Homework #5

1. Gas Mileage:  Exercise 4.17.  Call your class Mileage.java.  Place your pseudocode in a block comment.  Let a user's input of 0 miles driven serve as the sentinel value marking the end of input.  Your test cases should be in plain text files named mileage1.dat, mileage2.dat, and mileage3.dat, such that entering a command of the form "java Mileage < testFileName" will execute your mileage computation with the given testFileName as input data.  Note: the mileage computation over all tanks entered is the total miles divided by the total gallons.  Use floating point division for all calculations.

2. Largest:  Exercise 4.21.  Call your class Largest.java.  Place your pseudocode in a block comment.  Don't forget that the largest value can be negative.  Clarification: "Largest" means "greatest" in this context (i.e. >), rather than "largest magnitude".

3. Pig "Keep Pace and End Race" Advisor:  Call your class PigAdvisor.java.

Pig is a folk jeopardy dice game with simple rules: Two players race to reach 100 points. Each turn, a player repeatedly rolls a die until either a 1 ("pig") is rolled or the player holds and scores the sum of the rolls (i.e. the turn total). At any time during a player's turn, the player is faced with two decisions:

• roll - If the player rolls a
  • 1: the player scores nothing and it becomes the opponent's turn.
  • 2 - 6: the number is added to the player's turn total and the player's turn continues.
• hold - The turn total is added to the player's score and it becomes the opponent's turn.

Problem:  Given a player's score i, the opponent's score j, and the current turn total k, advise a player to "roll" or "hold" according to this "keep pace and end race" policy:

• If the player's score plus the turn total is greater than or equal to the goal score of 100, hold.
• Otherwise, if either player has a score greater than or equal to 71, roll.
• Otherwise, roll if and only if the turn total is less than 21 + round((j - i) / 8). (Use floating-point division before rounding.)

Input Format:

• integer player's score
• integer opponent's score
• integer turn total

Output Format:

• Prompt the user for each of the inputs above with "Player's score? ", "Opponent's score? ", and "Turn total? ", respectively.
• Given these inputs, output "roll" or "hold" according to the policy above.

Sample Transcripts (input underlined):

Player's score? 79
Opponent's score? 42
Turn total? 21
hold

Player's score? 37
Opponent's score? 71
Turn total? 48
roll

Player's score? 71
Opponent's score? 0
Turn total? 20
roll

Player's score? 42
Opponent's score? 57
Turn total? 22
roll

Player's score? 42
Opponent's score? 57
Turn total? 23
hold