Use this link to access the Deitel & Deitel home page for the textbook. In the left margin there is a link for downloading code and examples. You will be modifying the code from Figure 5.14 (the "craps" program). Download and study the program you will be modifying. Run the program several times and make sure you thoroughly understand how it works before you start working on this assignment.
initializeBalance This function prompts the user to enter a positive whole-dollar amount that will be used as the initial bank balance. A valid (i.e. positive) response is read in, and the value of the bank balance is returned by the function.
validWager This function checks the wager to make sure it doesn't exceed the player's current bank balance. If the wager is less than or equal to the current bank balance, the function returns 1 (true), otherwise it returns 0 (false).
playGame plays a single game of craps. It returns to the caller one of the enumerated constants WON or LOST. (This function is the one that contains most of the code from Figure 5.14.)
adjustBalance This function either adds the wager to or subtracts the wager from the player's current balance, depending upon whether the last game played was WON or LOST.
getYesOrNo This function asks if the player would like to play another game of craps. The function checks the response to make sure it is either 'y' or 'n'. The function will repeatedly ask for a y/n response until a valid response is entered. The answer (either 'y' or 'n') is returned to the calling function.
For each function you should write pre- and post-conditions, design the function as a black box (you don't have to turn in the black box), define a prototype, write a stub, and, once the program compiles successfully with each stub, fill in the function definitions (one at a time).
You may assume that when the program asks for a number, the user enters a number.
When the program asks for a character ('y' or 'n'), you may not make any assumptions about what the user enters. See the note about mixed numeric and character input, below.
Enter initial bank balance (positive, whole-dollar amount): 1000 Balance = $1000 Enter wager: 100 Player rolled 5 + 6 = 11 Player wins Balance = $1100 Do you want to play another game? (y or n): y Enter wager: 1500 Your wager must not exceed your current balance. Enter a new wager: 900 Player rolled 3 + 1 = 4 Point is 4 Player rolled 4 + 5 = 9 Player rolled 5 + 5 = 10 Player rolled 5 + 6 = 11 Player rolled 3 + 3 = 6 Player rolled 3 + 5 = 8 Player rolled 6 + 2 = 8 Player rolled 1 + 5 = 6 Player rolled 3 + 5 = 8 Player rolled 5 + 6 = 11 Player rolled 3 + 1 = 4 Player wins Balance = $2000 Do you want to play another game? (y or n): 2000 You must answer y or n. Do you want to play another game? (y or n): y Enter wager: 2000 Player rolled 6 + 5 = 11 Player wins Balance = $4000 Do you want to play another game? (y or n): n Your final balance is $4000
ch = getchar();That still leaves the newline character in the input buffer. This becomes a problem if the user had typed in an invalid response like 1800 instead of y or n, because the next time you try to use getchar() to read in a valid response it will read in the 8 of the number 1800, not the user's new input value.Similar problems are encountered if you use getchar() after reading in a numeric value; scanf() reads in the characters for the numeric value, and leaves the next character to be read (the newline character) still in the input buffer. A quick way to fix this problem is to follow each input statement with the loop:
while (getchar() != '\n');(Notice the placement of the semi-colon. The loop body is empty.) This loop essentially reads the rest of the characters on the line, and ignores them, until it reaches the end of the line. The next time your program executes an input statement (either scanf() or getchar()) it will get the input from the next line typed by the user.