Problem Set 3

CMP 326: Programming Methods II
Lehman College, City University of New York
Spring 2014

This problem set covers material from Chapters 3 and 4.

It should be finished by Thurs. Feb. 27, however you may submit it up until the end of office hours on Thurs. March 11. To submit a program, you need to demonstrate (during office hours or class) your program and explain how it works. You may submit a program multiple times.

General guidelines:

• Tell the user what any output means. Don't assume that they know what the program does.
• Practice using Java conventions (i.e. variable names look like thisIsAVariableName, etc) when writing your code
• You may use either a keyboard scanner or a GUI to ask the user for input and return the output.

Problems

1. Guessing game (10 points)

   Write a guessing game program that asks the user to guess your secret number. If the guess is too high, write a message saying so and ask them to guess again. Similarly, if the guess is too low, write a message saying so and ask them to guess again. If they guess correctly, congratulate them and end the program. You can assume the user will only enter integers.

2. Expanding word (5 points)

   Write a program that asks the user for a word and prints back out a string in which the first letter of the input word appears once, followed the second letter appearing twice, followed by the third letter appearing three times, etc.

   For example, the word cat would be output as caattt, the word zebra would be output as zeebbbrrrraaaaa, and the word a would be output as a.

3. Pig Latin (10 points)

   Write a program that asks the user for a sentence and prints the translation of the sentence in the “language” Pig Latin. Each word in the sentence should be translated into Pig Latin in the following way:

   1) If the English word starts with one or more consonants, all consonants before the first vowel are removed from the front of the English word, and added to the end of it, keeping the order the same. The string “ay” is then added to the end of this string.
   
   2) If the English word starts with a vowel, append the string “hay” to the end of that word.
   
   Treat ‘y’ as a consonant if it is at the beginning of a word, and otherwise treat it as a vowel. You may assume that the only punctuation used in the sentence are periods and commas. The displayed sentence should have the same punctuation as the original sentence, but should be all lower-case.
   
   For example, the input hello should be displayed at ellohay, and the sentence The elephant ate a mango. should be displayed at ethay elephanthay atehay ahay angomay.


4. Grade Calculator (10 points)

   Write a program that asks the user for a list of grades, and returns the average of the grades. You can chose the format in which the grades are entered, but you should communicate this clearly to the user in the program.

   For example, if the user enters the grades 89 81 94, the program returns the average 88.

   Extra credit (5 points): Modify your program so that the user can enter a weight for each grade. The program then returns the weighted average of the grades.

   For example, if the user enters the grades 89 81 94 with the weights 0.25 0.25 0.5, the program returns the weighted average 89.5.

Submitting Your Problem Set

You should submit all problems for grading by the deadline (see class schedule for date). To submit a program, you need to demonstrate (during office hours or lab) your program and explain how it works.