Computer Science 111a - Fall Semester, 2003

Homework #10

due: by 5:00 on Dec. 10

Your task in this week's project is to make some changes to the animal guessing game program, to make it more exciting. When the computer guesses an animal incorrectly, your program should ask the user what animal she was thinking of. Your program will then ask the user for a question to distinguish between her animal and the one you guessed, and it will use this information to modify its decision tree! The information will then be saved to file, so that the next time someone plays the game the computer will be even "smarter". Here are details:

• If the computer guesses an animal that is not the one the user was thinking of, it should get information from the user and add it to the tree:
• Ask the user what animal she was thinking of -- and read in the animal name, which should be one word (e.g., dog).
• Ask the user for a question that has the answer yes for her animal and no for the animal that the computer just guessed -- and read in the question. When you ask for this, you should print out both animal names, e.g., What is a question that has the answer yes for an aardvark and no for a skunk. Note that you should also use the correct article: a or an, depending on whether the name begins with a consonant or a vowel. How can you print the name of the animal that the computer guessed? Well, it is in the question string, and if you search for the first space from the end of the string (with strrchr), the name begins at the next position.
• Add this new information to the tree by:
• Moving the record from the index i that you're at to index 2i + 1;
• Changing the record at index i to contain the user's question (be sure to change the questiontype field); and
• Adding a record at index 2i with a guess that contains the user's animal name: Is it an aardvark?You can use strcpy and strcat to form this question from the strings "Is it a(n)", the name of the animal, and "?". Be sure to initialize the questiontype field as well.
• Before ending the program, copy all of the information in the animal_tree array back out to the file animal.dat. To do this,
• Open the file for writing;
• Loop through the array and, at each index that has an i or g, write the index number, the letter, and the question into the file. Be sure to format the file exactly as it was previously, so that the next time you scanf from the file it will work correctly!
• Close the file.
• For this to work correctly, you will need to initialize the questiontype field in every cell of the array to some value other than i or g, prior to reading the date from animal.dat into the array in the initialize function.

What to submit. Your program should be in a file called hw10.c. Submit this homework by the due date with the command submit hw10 hw10.c