My C Blackjack program got stuck [closed] - c

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#include<stdlib.h>
#include<stdio.h>
#include<time.h>
#define CARD_MAX 52
typedef int Deck[CARD_MAX];
Deck deck;
int cardnumber = 0;
int playerwin = 0, dealerwin = 0, tie = 0;
int game();
void setupDeck(Deck deck);
void shuffleDeck(Deck deck);
void printCard(int card);
int pickCard(Deck deck, int cardnum);
void endProgram();
void playAgain();
main()
{
char yn;
srand(time(NULL));
setupDeck(deck);
shuffleDeck(deck);
again:
printf("Welcome! Do you wanna try your luck in a Blackjack Game? If so type 'y'.\n");
printf("If not type 'n' to close the program: ");
scanf_s("%c", &yn);
getchar();
if (yn == 'y')
game();
else if (yn == 'n')
{
printf("Looks like you aren't feeling lucky today! Comeback tomorrow!\n");
system("pause");
}
else
{
printf("Unknown character! Try again!\n");
goto again;
}
}
int game()
{
int card, cardvalue = 0, cardtype = 0, tcvp = 0, tcvd = 0;
int aceflagp = 0, faceflagp = 0, aceflagd = 0, faceflagd = 0, bjp = 0, bjd = 0;
int loopcounter;
char hitorpass;
system("cls");
printf("Your cards:\n");
for (loopcounter = 0; loopcounter < 2; loopcounter++)
{
card = pickCard(deck, cardnumber);
cardnumber++;
cardvalue = card % 13;
cardtype = card / 13;
printCard(cardvalue, cardtype);
if (cardvalue == 1)
{
aceflagp++;
cardvalue = 11;
}
else if (cardvalue == 0 || cardvalue == 11 || cardvalue == 12)
{
faceflagp = 1;
cardvalue = 10;
}
else
cardvalue = cardvalue;
tcvp += cardvalue;
}
if (aceflagp == 1 && faceflagp == 1)
bjp = 1;
printf("Dealers cards:\n");
card = pickCard(deck, cardnumber);
cardnumber++;
cardvalue = card % 13;
cardtype = card / 13;
printCard(cardvalue, cardtype);
if (cardvalue == 1)
{
aceflagd++;
cardvalue = 11;
}
else if (cardvalue == 0 || cardvalue == 11 || cardvalue == 12)
{
faceflagd = 1;
cardvalue = 10;
}
else
cardvalue = cardvalue;
tcvd += cardvalue;
card = pickCard(deck, cardnumber);
cardnumber++;
cardvalue = card % 13;
cardtype = card / 13;
if (cardvalue == 1)
{
aceflagd++;
cardvalue = 11;
}
else if (cardvalue == 0 || cardvalue == 11 || cardvalue == 12)
{
faceflagd = 1;
cardvalue = 10;
}
else
cardvalue = cardvalue;
tcvd += cardvalue;
if (aceflagd == 1 && faceflagd == 1)
bjd = 1;
if (bjp == 1 && bjd == 1)
{
printf("Both sides has Blackjack! Tie!\n");
tie++;
playAgain();
}
else if (bjp == 1)
{
printf("Player Blackjack!\n");
playerwin++;
playAgain();
}
else if (bjd == 1)
{
printf("Dealer Blackjack!\n");
dealerwin++;
playAgain();
}
printf("Your card total is %d.\n", tcvp);
again:
printf("If you want to hit type 'h'. If you want to pass type 'p'");
scanf_s("%c", &hitorpass);
getchar();
if (hitorpass == 'h')
{
card = pickCard(deck, cardnumber);
cardnumber++;
cardvalue = card % 13;
cardtype = card / 13;
printCard(cardvalue, cardtype);
if (cardvalue == 1)
{
aceflagp++;
cardvalue = 11;
}
else if (cardvalue == 0 || cardvalue == 11 || cardvalue == 12)
{
faceflagp = 1;
cardvalue = 10;
}
else
cardvalue = cardvalue;
tcvp += cardvalue;
if (tcvp > 21)
{
if (aceflagp > 0)
{
tcvp -= 10;
aceflagp--;
printf("Your card total is %d.\n", tcvp);
goto again;
}
else
{
printf("Your hand busted. You lost!\n");
dealerwin++;
playAgain();
}
}
else if (tcvp == 21)
{
printf("You have 21 in your hand can't hit more!\n");
goto dealersturn;
}
else if (tcvp < 21)
{
printf("Your card total is %d.\n", tcvp);
goto again;
}
}
else if (hitorpass == 'p')
{
dealersturn:
printf("Dealers turn:\n");
if (tcvd < 17)
{
card = pickCard(deck, cardnumber);
cardnumber++;
cardvalue = card % 13;
cardtype = card / 13;
printCard(cardvalue, cardtype);
if (cardvalue == 1)
{
aceflagd++;
cardvalue = 11;
}
else if (cardvalue == 0 || cardvalue == 11 || cardvalue == 12)
{
faceflagd = 1;
cardvalue = 10;
}
else
cardvalue = cardvalue;
tcvd += cardvalue;
if (tcvd > 21)
{
if (aceflagd > 0)
{
tcvd -= 10;
aceflagd--;
goto dealersturn;
}
else
{
printf("Dealers has a total of %d. Dealers hand busted!\n", tcvd);
playerwin++;
playAgain();
}
}
else if (tcvd < 17)
goto dealersturn;
else
{
if (tcvp > tcvd)
{
printf("Player has %d, dealer has %d. Player won!", tcvp, tcvd);
playerwin++;
playAgain();
}
else if (tcvp == tcvd)
{
printf("Both player and the dealer has %d. Tie!", tcvd);
tie++;
playAgain();
}
else
{
printf("Player has %d, dealer has %d. Dealer won!", tcvp, tcvd);
dealerwin++;
playAgain();
}
}
}
}
else
{
printf("Unknown character. Try again!");
goto again;
}
system("pause");
}
void endProgram()
{
printf("Thanks for playing my blackjack game! The results are:\n");
printf("Player won %d times!\n", playerwin);
printf("Dealer won %d times!\n", dealerwin);
printf("There have been a tie %d times!\n", tie);
system("pause");
}
void playAgain()
{
char chardummy;
again:
printf("Would you like to play again? Type 'y' for Yes and 'n' for No.\n");
scanf_s("%c", &chardummy);
getchar();
if (chardummy == 'y')
{
if (cardnumber >= 48)
{
printf("There is not enough card left in the deck!");
endProgram();
}
else
game();
}
else if (chardummy == 'n')
endProgram();
else
{
printf("Unknown character. Try again!");
goto again;
}
}
void setupDeck(Deck deck)
{
int i;
for (i = 0; i<CARD_MAX; i++)
{
deck[i] = i;
}
}
void shuffleDeck(Deck deck)
{
for (int i = 52 - 1; i >= 0; --i) {
int r = rand() % (i + 1);
int t = deck[i];
deck[i] = deck[r];
deck[r] = t;
}
}
void printCard(int cardvalue, int cardtype)
{
char cardtype2;
if (cardtype == 0)
cardtype2 = 'C';
else if (cardtype == 1)
cardtype2 = 'D';
else if (cardtype == 2)
cardtype2 = 'H';
else if (cardtype == 3)
cardtype2 = 'S';
switch (cardvalue)
{
case 0:
{
printf("*******\n");
printf("* *\n");
printf("* %c *\n", cardtype2);
printf("* K *\n", cardvalue);
printf("* *\n");
printf("*******\n");
break;
}
case 1:
{
printf("*******\n");
printf("* *\n");
printf("* %c *\n", cardtype2);
printf("* A *\n");
printf("* *\n");
printf("*******\n");
break;
}
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
case 9:
case 10:
{
printf("*******\n");
printf("* *\n");
printf("* %c *\n", cardtype2);
printf("* %2d *\n", cardvalue);
printf("* *\n");
printf("*******\n");
break;
}
case 11:
{
printf("*******\n");
printf("* *\n");
printf("* %c *\n", cardtype2);
printf("* J *\n", cardvalue);
printf("* *\n");
printf("*******\n");
break;
}
case 12:
{
printf("*******\n");
printf("* *\n");
printf("* %c *\n", cardtype2);
printf("* Q *\n", cardvalue);
printf("* *\n");
printf("*******\n");
break;
}
}
}
int pickCard(Deck deck, int cardnum)
{
if (cardnumber == 52)
{
printf("There is not enough cards left to complete the game!");
endProgram();
}
else
return deck[cardnum];
}
Here is my code for a simple blackjack game. For some reason after some rounds Dealers turn does not work. I would be gratefull if you could find the reason as I couldn't. And feel free to give tips about improving my code.

Answer 1

You have the following problems in your code that I could see from compiler warnings/errors.
The declaration of printCard does not match its usage and its implementation. Change the declaration to:
void printCard(int cardvalue, int cardtype);
Make the return type of main explicit. Change it to:
int main () ...
Change the lines that print K, J, and Q. You don't need the additional argument to printf in those lines.
printf("* K *\n");
printf("* J *\n");
printf("* Q *\n");
Of the above, the first one is the most crucial fix. With those changes, I was able to run your program without any problem. My test platform: Linux, gcc 4.8.4.
Increase your warning level so you can detect such warnings/errors and fix them in future programming efforts.

Answer 2

Since you asked... :-)
In addition to what R Sahu called out...
The biggest problem (challenge?) I noticed is that I don't see how your endProgram() function actually 'ends' anything. It calls system("pause") and then resumes:
void endProgram()
{
printf("Thanks for playing my blackjack game! The results are:\n");
printf("Player won %d times!\n", playerwin);
printf("Dealer won %d times!\n", dealerwin);
printf("There have been a tie %d times!\n", tie);
system("pause);
}
Which means code like the following in the pickCard() function has unpredictable behavior:
int pickCard(Deck deck, int cardnum)
{
if (cardnumber == 52)
{
printf("There is not enough cards left to complete the game!");
endProgram(); // once we get here what do we return to the caller?
}
else
return deck[cardnum];
}
By "unpredictable" I specifically mean: What will pickCard() return to for cardnumber = 52 ?
I suspect pickCard() is going to call endProgram(), whch being a void function won't do anything but return, then pickCard will fall out of the if-else statement and try to return an integer to the caller, and it will probably be choosing some garbage off the call stack to send back which may (or may not) be a valid card value.
It turns out you call pickCard() in roughly 5 different places, sometimes for the player, sometimes the dealer.
What happens to that logic if pickCard() returns a value that is way out of bounds?
Since you only call shuffleDeck() once at the beginning of main(), eventually you're going to 'exhaust' the deck and get an undefined card value returned from pickCard().
Which kind of fits your symptoms of "it breaks in Dealer after a while...".
So... for general cleanup...
I would take most the variables you have in the game() method and make them globals.
I would add a LOT of print statements for debugging so you can verify the code is doing what you think it will do.
Your calls to system() are a challenge for me on the linux side of the fence:
system("cls");
system("pause");
Since you're devleoping on Windows I understand why you are using system (reminds me of the ancient days when I used to write dos batch files).
But... I would encourage you to ditch the system() calls and write your own input "helper" function that deals with scanf_s or whatever you want to use.
Maybe something like this that can take a prompt and return whatever character the user types.
char prompt_and_read_char( char *msg );
I would encourage you to rewrite without goto statements.
You do attempt a loop in the game() function for the player to draw cards; the for loop, so bonus points for that.
Your overall style and user interaction goals are sound and suggest you'll eventually make a fun game.
The code in game() is a bit over 200 lines of code, which makes it is harder than it needs to be to read.
I would suggest doing something like this in game() function: the goal is to push all card-drawing into functions just for the player, or the dealer.
// Global Variable definitions...
int gameInProcess = 0; // global, set to false.
int tcvp = -1; // obvious bad
// note for global-var police: yeah, I know globals is not "good style".
// But cut our beginning programmer some slack here... this seems like the easiest way for
// them to get their game running. (Think of it as a first step toward cleaning up the
// game() method if that helps any).
// prototypes here.
// main() here.
...etc...
int game() {
gameInProcess = 1; // set to true.
tcvp = 0;
tcvd = 0;
while( gameInProcess ) {
// add plenty of print statements so you see what is going on; you can clean
// them up later by searching on DEBUG.
printf("DEBUG... game(): tcvp=%d tcvd=%d cardnumber=%d\n", tcvp, tcvd, cardnumber );
game_playerDraws( ); // updates tcvp, may set gameInProcess to 0 if player win or busts.
game_dealerDraws( ); // udpates tcvd, may set gameInProcess to 0 if dealer hits blackjack or goes bust.
...other functions for variations...
}
printf("game over, score: player=%d dealer=%d\n", tcvp, tcvd );
// add logic to decide winner.
// return to caller, maybe let them decide if we'll have another game using the same deck.
}
game_playerDraws( ) {
if( !gameInProcess ) {
printf("game_playerDraws(): gameInProcess=%d, nothing to do.\n", gameInProcess );
return;
}
// draw some cards, update globalcs if player wins or breaks.
}
game_dealerDraws( ) {
... do dealer-approriate things...
}
The upside of this is if you exahust the deck, you can just set gameInProcess = 0; and return and everything gracefully stops.
You might add an option to shuffle a new deck and start another game.
But the big advantage is it will give you a clean way to start and end each game, which is something you're missing in the current version of the code.
Good luck. You clearly enjoy programming and are having fun with the writing game.
Stick with it, I think you'll learn a lot.