Thread: Tic Tac Toe program problem

I have to make a tic tac toe program and I am struggling. This is the function that I have currently. This function is suppose to determine if there is a winner or a Cats game. With this function, my program places a X or an O wherever the user has typed they want it. (This works) but it only runs once and that is where I am struggling. I need it to run until it finds a winner or if it a Cats game. Any help would be appreciated.

Code:

int checkForWin(int *piece, char *letter){
	int r,c;
	char board[3][3]={{'1','2','3'},
				  {'4','5','6'},
			      	  {'7','8','9'}};					  


		if (&*letter=='x' || &*letter=='X')
		{
			printf("\nYou are player X.\n\n");
		} 
		else printf("\nYou are player O.\n\n");


			if ((&*letter=='x' || &*letter=='X') && &*piece==1)
			{
				board[0][0]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==2)
			{
				board[0][1]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==3)
			{
				board[0][2]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==4)
			{
				board[1][0]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==5)
			{
				board[1][1]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==6)
			{
				board[1][2]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==7)
			{
				board[2][0]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='x' || &*letter=='X') && &*piece==8)
			{
				board[2][1]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			 
			if ((&*letter=='x' || &*letter=='X') && &*piece==9)
			{
				board[2][2]='X';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==1)
			{
				board[0][0]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==2)
			{
				board[0][1]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==3)
			{
				board[0][2]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==4)
			{
				board[1][0]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==5)
			{
				board[1][1]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==6)
			{
				board[1][2]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==7)
			{
				board[2][0]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			
			if ((&*letter=='o' || &*letter=='O') && &*piece==8)
			{
				board[2][1]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}
			 
			if ((&*letter=='o' || &*letter=='O') && &*piece==9)
			{
				board[2][2]='O';
					for (r=0;r<3;r++)
					{
		
						for (c=0;c<3;c++)
						{
						printf("%c ",board[r][c]);
									
						}					
					if (r==0 || r==1)
					{
					printf("\n");	
					}
					}
			}    
		
return 0;	
}

Originally Posted by gemera

Well, a few things:

If you haven't enabled your compiler warnings you should do so - it will make your coding experience a lot easier. If you don't know how, try googling on your compiler version.

Code:

if ((&*letter=='o' || &*letter=='O') && &*piece==9)

This code and your various versions of it are wrong. You probably wanted

Code:

if ((*letter=='o' || *letter=='O') && *piece==9)

I tried that and my program crashes whenever I run it. It works the way I put it or when I take out &* and keep it as letter=='o'.

The function appears to be a player move function rather than one to check for the game end, and includes 18 occurences of the code:

Code:

                        for (r=0;r<3;r++){
         
                            for (c=0;c<3;c++)
                            {
                                 printf("%c ",board[r][c]);
          
                            }                   
                            if (r==0 || r==1)
                            {
                                printf("\n");   

                            }
                        }

So your code could be greatly simplified by placing the board drawing code in its own function.

That will give you a start to fixing some of the issues, but it would probably help you even more to forget the code for a moment and sit down with paper and pen and plan your program out by breaking it down into well defined functions.

I am completely lost right now. Can you push me in the right direction?

Post your complete code.

Originally Posted by gemera

Post your complete code.

Code:

#include<stdio.h>
void displayBoard();
int selectLocation(int *);
int setTurn(char *);
void checkForWin();


int main()
{
int *piece;
char yes, *letter;


    do
    {
    displayBoard();    
    selectLocation(&piece);
    setTurn(&letter);
    checkForWin();


    printf("\n\n\nPress Y if you want to play again.\n");
    scanf("\n%c",&yes);
    } while (yes=='y' || yes=='Y');


return 0;
}


void displayBoard()
{
    int r,c;
    char board[3][3]={{'1','2','3'},
                      {'4','5','6'},
                      {'7','8','9'}};
    printf("\nHello, \n\nThis is your game board.\n\n");
    
    for (r=0;r<3;r++)
    {
        
        for (c=0;c<3;c++)
        {
        printf("%c ",board[r][c]);            
        }
        if (r==0 || r==1)
        {
        printf("\n");    
        }
    }    
}
    
int selectLocation(int *piece)
{        
    do
    {
        printf("\n\nPlease type the number where you want to place your piece: ");        
        scanf("%d",piece);    
    
        if (*piece!=1&& *piece!=2&& *piece!=3 && *piece!=4 && *piece!=5 && *piece!=6 && *piece!=7 && *piece!=8 && *piece!=9)
        {        
        printf("\n\nEror: Not a correct number. Please try again\n\n");    
        }
        
    }while (*piece!=1&& *piece!=2&& *piece!=3 && *piece!=4 && *piece!=5 && *piece!=6 && *piece!=7 && *piece!=8 && *piece!=9);
    
    
return *piece;    
}


int setTurn(char *letter)
{
    do
    {
        printf("\n\nDo you want to place a X or an O? ");        
        scanf("\n%c",letter);    
    
        if (*letter!='x' && *letter!='X' && *letter!='o' && *letter!='O')
        {        
        printf("\n\nEror: Not a correct option. Please try again\n\n");    
        }
    }while (*letter!='x' && *letter!='X' && *letter!='o' && *letter!='O');
            
return *letter;    
}

Here it is without the checkForWin. I changed it from an int to a void trying to get it work but I am still stuck.

Don't have the time to check it in detail ( maybe some of the other guys will chime in )

But if you are passing your piece and letter variables from main() like that, they shouldn't be pointers.

What you want is

int piece;

char letter;

Also whereas its good that you now have a function to print the board, the actual declaration of the array for the board should be in main() so that you can pass it to the various functions that need it, including displayBoard().

Originally Posted by gemera

Don't have the time to check it in detail ( maybe some of the other guys will chime in )

But if you are passing your piece and letter variables from main() like that, they shouldn't be pointers.

What you want is

int piece;

char letter;

Also whereas its good that you now have a function to print the board, the actual declaration of the array for the board should be in main() so that you can pass it to the various functions that need it, including displayBoard().

I tried changing *piece to piece used a printf to see what it was returning and it was no longer returning the value. It would always return 0.

Look at this snippet:

Code:

 
int main()
{
int *piece;
char yes, *letter;

Where are you allocating memory to those pointers?

Jim

Originally Posted by jimblumberg

Look at this snippet:

Code:

 
int main()
{
int *piece;
char yes, *letter;

Where are you allocating memory to those pointers?

Jim

What do you mean exactly? I declared them there and I declared them in their own functions.

Code:

intselectLocation(int*piece){        
    do
    {
        printf("\n\nPlease type the number where you want to place your piece: ");        
        scanf("%d",piece);    

        if (*piece!=1&& *piece!=2&& *piece!=3 && *piece!=4 && *piece!=5 && *piece!=6 && *piece!=7 && *piece!=8 && *piece!=9)
        {        
        printf("\n\nEror: Not a correct number. Please try again\n\n");    
        }

    }while (*piece!=1&& *piece!=2&& *piece!=3 && *piece!=4 && *piece!=5 && *piece!=6 && *piece!=7 && *piece!=8 && *piece!=9);


return *piece;    
}


int setTurn(char *letter)
{
    do
    {
        printf("\n\nDo you want to place a X or an O? ");        
        scanf("\n%c",letter);    

        if (*letter!='x' && *letter!='X' && *letter!='o' && *letter!='O')
        {        
        printf("\n\nEror: Not a correct option. Please try again\n\n");    
        }
    }while (*letter!='x' && *letter!='X' && *letter!='o' && *letter!='O');

return *letter;    
}

I mean where have you allocated memory for those pointers? Just declaring a pointer variable doesn't provide memory for the pointers, you need to either allocate memory using malloc() or use assignment to point to an existing variable.




Jim

Originally Posted by jimblumberg

I mean where have you allocated memory for those pointers? Just declaring a pointer variable doesn't provide memory for the pointers, you need to either allocate memory using malloc() or use assignment to point to an existing variable.




Jim

Oh yeah. I forgot to do that. I'll look into it when I get home.

But do note, you probably shouldn't be using the pointers in main(), just use "standard" non-pointer variables. Also several of your functions should probably be returning nothing (void) because you're trying to pass the parameters by pointer, which means that the changes made in the functions will be reflected in the calling functions.

Jim

@Kobeissi2

Reviewing chapters on pointers and functions in your C book would be a good idea.

That should give you the necessary confidence and understanding in passing variables and arrays to functions.

Originally Posted by jimblumberg

But do note, you probably shouldn't be using the pointers in main(), just use "standard" non-pointer variables. Also several of your functions should probably be returning nothing (void) because you're trying to pass the parameters by pointer, which means that the changes made in the functions will be reflected in the calling functions.

Jim

I fixed it this way and it works now. I just don't know how to actually determine the winner.

Code:

#include<stdio.h>
void displayBoard();
int selectLocation(int);
char setTurn(char);
void checkForWin(int, char);


int main()
{
int piece;
char yes, letter;


    do
    {
    displayBoard();    
    piece=selectLocation(piece);
    letter=setTurn(letter);
    checkForWin(piece, letter);
    
    printf("\n\n\nPress Y if you want to play again.\n");
    scanf("\n%c",&yes);
    } while (yes=='y' || yes=='Y');


return 0;
}


void displayBoard()
{
    int r,c;
    char board[3][3]={{'1','2','3'},
                      {'4','5','6'},
                      {'7','8','9'}};
    printf("\nHello, \n\nThis is your game board.\n\n");
    
    for (r=0;r<3;r++)
    {
        
        for (c=0;c<3;c++)
        {
        printf("%c ",board[r][c]);            
        }
        if (r==0 || r==1)
        {
        printf("\n");    
        }
    }    
}
    
int selectLocation(int piece)
{    
    int *piecePtr;
    piecePtr=&piece;    
    do
    {
        printf("\n\nPlease type the number where you want to place your piece: ");        
        scanf("%d",&piece);    
    
        if (*piecePtr!=1&& *piecePtr!=2&& *piecePtr!=3 && *piecePtr!=4 && *piecePtr!=5 && *piecePtr!=6 && *piecePtr!=7 && *piecePtr!=8 && *piecePtr!=9)
        {        
        printf("\n\nEror: Not a correct number. Please try again\n\n");    
        }
        
    }while (*piecePtr!=1&& *piecePtr!=2&& *piecePtr!=3 && *piecePtr!=4 && *piecePtr!=5 && *piecePtr!=6 && *piecePtr!=7 && *piecePtr!=8 && *piecePtr!=9);
    
    return piece;
}


char setTurn(char letter)
{
    char *letterPtr;
    letterPtr=&letter;
    do
    {
        printf("\n\nDo you want to place a X or an O? ");        
        scanf("\n%c",&letter);    
    
        if (*letterPtr!='x' && *letterPtr!='X' && *letterPtr!='o' && *letterPtr!='O')
        {        
        printf("\n\nEror: Not a correct option. Please try again\n\n");    
        }
    }while (*letterPtr!='x' && *letterPtr!='X' && *letterPtr!='o' && *letterPtr!='O');
    
    return letter;
}


void checkForWin(int piece, char letter)
{
     int r,c;
     char board[3][3]={{'1','2','3'},
                       {'4','5','6'},  
                       {'7','8','9'}};        
}

Originally Posted by gemera

@Kobeissi2

Reviewing chapters on pointers and functions in your C book would be a good idea.

That should give you the necessary confidence and understanding in passing variables and arrays to functions.

I do not have a C book. I got that part working though. I just do not truly understand how to determine the winner. I also do not know how to keep giving the player turns until someone wins.