handout #6
CSE142—Computer
Programming I
Programming
Assignment #5
due:
Wednesday, 7/26/17, 11 pm
This assignment will give you practice with while loops and
pseudorandom numbers. You are going to
write a program that allows the user to play a simple guessing game in which
your program thinks up an integer and allows the user to make guesses until the
user gets it right. For each incorrect
guess you will tell the user whether the right answer is higher or lower. Your program is required to exactly reproduce the format and
behavior of the log of execution at the end of this write-up.
At a minimum, your program should have the following static
methods in addition to method main:
·
a
method that introduces the game to the user
·
a
method to play one game with the user (just one game, not multiple games)
·
a
method to report overall results to the user
You may define more methods than this if you find it
helpful, although you will find that the limitation that methods can return
only one value will tend to limit how much you can decompose this problem.
You are to define a class constant for the maximum number
used in the guessing game. The sample
log shows the user making guesses from 1 to 100, but the choice of 100 is
arbitrary. By introducing a constant for
100, you should be able to change just the value of the constant to make the
program play the game with a range of 1 to 50 or a range of 1 to 250 or some
other range starting with 1.
When you ask the user whether or not to play again, you
should use the “next()” method of the Scanner class to
read a one-word answer from the user.
You should continue playing if this answer begins with the letter “y” or
the letter “Y”. Notice that the user is
allowed to type words like “yes”. You are
to look just at the first letter of the user’s response and see whether it
begins with a “y” or “n” (either capitalized or not) to determine whether to
play again.
Assume that the user always types an integer when guessing,
that the integer is always in an appropriate range and that the user gives you
a one-word answer beginning with “y”, “Y”, “n” or “N” when asked whether to
play again. You may assume that no game
involves more than 9,999 guesses.
You will
notice at the end of the log that you are to report various statistics about
the series of games played by the user.
You are to report the total number of games played, the total number of
guesses made (all games included), the average number of guesses per game, and
the best (fewest) number of guesses used in any single game. The average number of guesses per games
should be rounded to one decimal place (you can use either the round1 method or
a printf).
Because this program uses pseudorandom numbers, you won’t be
able to recreate the sample log. We will
provide sample logs where the answer is always 42. Obviously you won’t want your program to
always pick 42 as the number to be guessed.
You should modify your program to set the answer to 42 and check its
behavior against the sample logs. Then
you should put it back to the normal behavior of picking a different number for
every game before you turn it in.
Here are a few helpful hints to
keep in mind.
You
should handle the case where the user guesses the correct number on the first
try. Print the following message:
You got it right in 1 guess
In the
last program we asked you to write very short methods that were no longer than
15 lines long and to have a very short main.
This program is more difficult to decompose into methods, so you may end
up having methods that are longer than 15 lines. You can also include more code in your main
method than we allowed in the last program.
In particular, you are required to have a while loop in main that plays
multiple games and prompts the user for whether or not to play another
game. You shouldn’t have all of the code
in main because you are required to have the methods described at the beginning
of this write-up.
We will
once again expect you to use good programming style and to include useful
comments throughout your program. We
will expect you to make appropriate choices about when to store values as int versus double, which if/else constructs to use, what
parameters to pass, and so on.
For this
assignment you are limited to the language features in Chapters 1-5 shown in
lecture or the textbook. You are not
allowed to use the break statement or to have a return statement in a void
method because these often lead to bad style.
Use
whitespace and indentation properly.
Limit lines to 100 characters.
Give meaningful names to methods and variables, and follow Java's naming
standards. Localize variables whenever
possible. Include a comment at the
beginning of your program with basic description information and a comment at
the start of each method. Some
students try to achieve repetition without properly using while loops, by
writing a method that calls itself; this is not appropriate on this assignment
and will result in a deduction in points
Your
program should be stored in a file called Guess.java.
Log of
execution (user input bold and underlined)
This
program allows you to play a guessing game.
I
will think of a number between 1 and
100
and will allow you to guess until
you get it. For each guess, I will tell you
whether the right answer is higher or
lower
than your guess.
I'm
thinking of a number between 1 and 100...
Your
guess? 50
It's
lower.
Your
guess? 25
It's
lower.
Your
guess? 12
It's
lower.
Your
guess? 6
You
got it right in 4 guesses
Do
you want to play again? y
I'm
thinking of a number between 1 and 100...
Your
guess? 50
It's
lower.
Your
guess? 25
It's
lower.
Your
guess? 12
It's
higher.
Your
guess? 18
You
got it right in 4 guesses
Do
you want to play again? YES
I'm
thinking of a number between 1 and 100...
Your
guess? 50
It's
higher.
Your
guess? 75
It's
lower.
Your
guess? 62
It's
higher.
Your
guess? 68
It's
lower.
Your
guess? 65
It's
higher.
Your
guess? 66
It's
higher.
Your
guess? 67
You
got it right in 7 guesses
Do
you want to play again? nope
Overall
results:
total games = 3
total guesses = 15
guesses/game = 5.0
best game = 4