Saving Data in a Basic Tic-Tac-Toe Game - c

Question

I'm relatively new to C. In Kochan's "Programming in C" I'm currently on if-else statements. I'm trying to program a basic tic-tac-toe game but I've run into some difficulty. I'm not sure how to save the board once a player has placed an x or an o. Here's the code I have so far:
#include <stdio.h>
int main (void)
{
int board = "_|_|_\n
_|_|_\n
| | \n";
int player1, player2;
printf ("Print %i", board)
printf("Player 1, it's your move:")
scanf("%i", player1)
if(player1 == "upLeft")
printf("x|_|_\n
_|_|_\n
_|_|_\n
etc.
Am I still too much of a beginner to implement this feature?

Answer 1

First of all, this doesn't make sense:
int board = "_|_|_\n
_|_|_\n
| | \n";
An int is not a string, and you can't assign a string to an int. In C, strings are arrays of characters:
char board[] = "_|_|_\n_|_|_\n | | \n";
That makes more sense. But it's really not a good way to store the state of a tic tac toe board. What you should do instead is store some value for each position on the board. Don't worry about the actual format of the board, you can format it as you like when you display it. So store your board this way:
char board[9] = "---------";
where a "-" means the space is empty. When the player moves, you replace the character at the appropriate position in the array with an "X" or an "O" (or 1 and 2, or any other values that work for you). When you get some input from the user, you'll change just the corresponding value in the board array. If you number the positions 0-8 starting from the top left corner, the rightmost position in the middle row would be position 5, for example. (Remember, C arrays are zero-based, so the first index is 0.) So if the user wants to put an X at that spot, you'd say:
board[5] = 'X';
Next, you might want to write a function that prints the board. That is where you'll insert whatever characters you like to draw the board.
Finally, you're going to want to use some sort of loop to repeatedly read the user's input, modify the state of the board, print the board, and maybe display a prompt.

Answer 2

First-things-first, you cannot store
"_|_|_\n
_|_|_\n
| | \n";
in an integer variable. You need variables of other types (like char *, char a[][], etc).
OTOH, the pseudocode is as follows. Please try and follow this to write a C program on your own.
Let row = 3 and column = 3
Declare an array[row][column] and fill it all with 0
Let 1 represent the input of user-1 and 2 represent the input of user-2 (in the array)
i.e. if a[2][2] = 1 means, user-1 marked that location.
while ( ! all_locations_filled() ) {
take input from user-1
if user-1 chooses a valid_location(location) to mark, then mark_location(user-1, location)
check if user-1 won_the_game(user-1), if so break and congratulate user-1!
take input from user-2
if user-2 chooses a valid_location(location) to mark, then mark_location(user-2, location)
check if user-2 won_the_game(user-2), if so break and congratulate user-2!
}
valid_location(location l)
{
return array[l.row][l.column] == 0;
}
mark_location(user u, location l)
{
array[l.row][l.column] = (u==user-1) ? 1 : 2;
}
display_board()
{
for i=0 to row
for j=0 to col
if array[i][j] == 0 print ""
else print array[i][j]
/* print blank when that location is not yet marked */
}
all_locations_filled()
{
for i=0 to row
for j=0 to col
if array[i][j] == 0
return false
return true
}
won_the_game(user u)
{
/* You need to write the logic here */
:P
}

Answer 3

You can use a 2d array to represent the board, and maybe some small int, with 0 as nothing there, 1 as X and 2 as 0.
You cant save the like that
int board = "X|_|_\n
_|_|_\n
| | \n";
you can have something like board[0][0]=1;
then you can iterate that array and if its 1 print the X.

Answer 4

It's a bit of a beginner question, but you're a beginner, so that's okay! Let's go with some leading questions:
So, you're saying you want to save the board state. What do you want to save? At any point in the program, what do you want to be able to look up? The history of the moves? What the board looks like? What each corner contains? Each of these suggests a different way to change a variable when you get some input from the user.
As other people have said, you can't do all those things with int type, and even if you could, this program is still way too hard and frustrating until you have a few more tools in your toolbox. Chapter 7 is Arrays, which will be very useful, and Chapter 10 is Character Strings, which will show you how to deal with all these strings the right way in C. So my suggestion to you is go through a few more chapters of the book and the big picture will start to make a bit more sense. Happy hacking!

Answer 5

Here is a small template like thing I have given write your own logic inside the GetBestMove() function for the computers move (if you are building AI) else replace the call for the GetBestMove by GetMove function in the StartGame function
#include<stdio.h>
#define HUMAN_WIN 1
#define DRAW 0
#define HUMAN_LOSE -1
#define HUMAN_COIN 'X'
#define COMP_COIN 'O'
#define DEFAULT 0xFFF
int main(void)
{
StartGame();
}
enum turnOf{ Human = 0, Computer};
enum gameEndState{Lose = -1, Draw, Win};
int humanMove = 1;
int computerMove = 1;
char _board[3][3] = {'-', '-', '-', '-', '-', '-', '-', '-', '-'};
void StartGame()
{
enum turnOf turn = 0;
enum gameEndState state = -2;
while(1)
{
turn = 1 - turn;
if(turn == Human)
{
GetMove();
UpdateBoard(humanMove, turn);
}
else if(turn == Computer)
{
GetBestMove(turn);
UpdateBoard(computerMove, turn, _board);
}
state = win(_board);
switch(state)
{
case Win:
NotifyUser("You win.");exit(0);
case Draw:
NotifyUser("Match draw.");exit(0);
case Lose:
NotifyUser("You Lose.");exit(0);
}
}
}
int depth = 0;
int GetBestMove(enum turnOf turn, int *x, int *y)
{
depth++;
int i, j, MOV = -10, BESTMOVx, BESTMOVy;
enum turnOf now = turn;
char pebble = (now == Human) ? HUMAN_COIN : COMP_COIN;
for(i=0; i<3; i++)
{
for(j=0; j<3; j++)
{
if(_board[i][j] == '-')
{
_board[i][j] = pebble;
now = 1 - now;
int condition = win(_board);
if(condition != DRAW || condition != DEFAULT)
{
return (condition == HUMAN_LOSE) ? (depth - 10) : (10 - depth);
}
else
{
int state = GetBestMove(now, BESTMOVx, BESTMOVy);
if(state > MOV)
{
MOV = state;
}
}
}
}
}
}
int win(char a[3][3])
{
char pebble = HUMAN_COIN;
int i, j, p = 0;
i=0;
for(j = 0; j < 3; j++)
if(a[i][j] == pebble && a[i+1][j] == pebble && a[i+2][j] == pebble) return HUMAN_WIN;
j=0;
for(i = 0; i < 3; i++)
if(a[i][j] == pebble && a[i][j+1] == pebble && a[i][j+2] == pebble) return HUMAN_WIN;
if(a[0][0] == pebble && a[1][1] == pebble && a[2][2] == pebble) return HUMAN_WIN;
else if(a[0][2] == pebble && a[1][1] == pebble && a[2][0] == pebble) return HUMAN_WIN;
/// Recheck for lose
pebble = COMP_COIN;
i=0;
for(j = 0; j < 3; j++)
if(a[i][j] == pebble && a[i+1][j] == pebble && a[i+2][j] == pebble) return HUMAN_LOSE;
j=0;
for(i = 0; i < 3; i++)
if(a[i][j] == pebble && a[i][j+1] == pebble && a[i][j+2] == pebble) return HUMAN_LOSE;
if(a[0][0] == pebble && a[1][1] == pebble && a[2][2] == pebble) return HUMAN_LOSE;
else if(a[0][2] == pebble && a[1][1] == pebble && a[2][0] == pebble) return HUMAN_LOSE;
for(i = 0; i < 3; i++)
for(j = 0; j < 3; j++)
if(a[i][j] == '-') p++;
if(p == 0) return DRAW;
return DEFAULT;
}
void GetMove()
{
int x, y;
LoadFrame(_board);
printf("\nEnter your move : ");
humanMove = getche() - 48;
if(!(humanMove > 0 && humanMove < 10))
{
NotifyUser("Enter a valid location.");
GetMove();
}
GetCordinates(&x, &y, humanMove);
if(_board[x][y] != '-')
{
NotifyUser("The place is nonEmpty.");
GetMove();
}
}
void UpdateBoard(int move, enum turnOf player, char board[3][3])
{
int x, y;
char pebble = (player == Human) ? HUMAN_COIN : COMP_COIN;
GetCordinates(&x, &y, move);
board[x][y] = pebble;
LoadFrame(board);
}
void LoadFrame(char board[3][3])
{
int x, y;
system("cls");
for(x = 0; x < 3; x++)
{
printf("\n\t ");
for(y = 0; y < 3; y++)
{
printf(" %c ", board[x][y]);
}
}
}
void GetCordinates(int *x, int *y, int move)
{
switch(move)
{
case 1: *x = 0; *y = 0; break;
case 2: *x = 0; *y = 1; break;
case 3: *x = 0; *y = 2; break;
case 4: *x = 1; *y = 0; break;
case 5: *x = 1; *y = 1; break;
case 6: *x = 1; *y = 2; break;
case 7: *x = 2; *y = 0; break;
case 8: *x = 2; *y = 1; break;
case 9: *x = 2; *y = 2; break;
}
}
void NotifyUser(const char* message)
{
printf("\n\n%s\a", message);
getch();
system("cls");
LoadFrame(_board);
}