Thread: Simple TicTacToe game - feedback please!

Hi, wasn't sure if this post should go in the games section, but seemed more relevant here. Made this game - have only got to the arrays tutorial on this site btw. Have read around a bit and seems classes are useful for more advanced stuff (for this game)!

There's two parts I'm sure can be improved to start with. First one is the winnercheck function - seems a bit too brute force method. I can't think of a better way to check for a winner though. Second bit is my move function. Quite a bit of repitition here - would like to make it more compact.

Anyway here's my code, I hope it's understandable:

Code:

#include <iostream>

using namespace std;

//Prototype funcitons
char printarray(char board[3][3]); //Function to print the board
int winnercheck(char board[3][3], char letter, int *won); //Checks if someone has won the game
int move(char board[3][3], char letter, int *won); //Collects coordinates, validates input and uses above functions


int main()
{
    char board[3][3]={'-','-','-','-','-','-','-','-','-'}; //Initial board
    char board_start[4][4]={'-','1','2','3','1','-','-','-','2','-','-','-','3','-','-','-'}; //Showing input method (coordinates)
    char X,O; //Player 'pieces'
    int i,j; //For printing board_start array
    int x,y; //For placing X's and O's
    int won=0; //This will be set to 0 if no one has won and 1 is there is a winner. Changed by the winnercheck function.
    int turn=1; //Turn is set to 1 as Player 1 goes 1st

    //Introduction
    cout<<"Welcome to Tic-Tac-Toe\n";
    for(i=0;i<4;i++) //Show game board coordinates
    {
        for(j=0;j<4;j++)
        {
            cout<<board_start[i][j]<<"\t";
        }
        cout<<"\n";
    }
    cout<<"Instructions: when asked, input the coordinates of where you want to go\n";
    cout<<"in the form of x y, where x is the row number(1-3) and y is the column\n";
    cout<<"number(1-3)\n";
    cout<<"e.g. to go in the middle square would be 2 2, or top right corner would be 1 3\n";
    cout<<"Player 1=X, Player 2=O" <<endl<<endl;
    //End of introduction

    //Game
    while(won==0)
    {
        switch (turn)
        {
            case 1:
                cout<<"Player 1, enter where you want to go: ";
                move(board,'X', &won);
                if(won==1) cout<<"Player 1 wins\n";
                turn=2;
                break;
            case 2:
                cout<<"Player 2, enter where you want to go: ";
                move(board,'O', &won);
                if(won==1) cout<<"Player 2 wins\n";
                turn=1;
                break;
        }
    }
}

char printarray(char board[3][3])
{
    int i,j;

    cout<<"\n";

    for(i=0;i<3;i++)
    {
        for(j=0;j<3;j++)
        {
            cout<<board[i][j]<<"\t";
        }
        cout<<"\n";
    }
}

int move(char board[3][3], char letter, int *won)
{
    int x,y,range,check;

    cin>> x>>y;
    x-=1; y-=1;
    range = x<0 || x>2 || y<0 || y>2;
    check = board[x][y] == 'X' || board[x][y] == 'O';

    while(range || check)
    {
        if (range) cout<<"Coordinates out of range. Try again: ";
        if (check) cout<<"Position already taken. Try again: ";
        cin>> x >>y;
        x-=1; y-=1;
        range = x<0 || x>2 || y<0 || y>2;
        check = board[x][y] == 'X' || board[x][y] == 'O';
    }
    board[x][y] = letter;
    printarray(board);
    winnercheck(board, letter, won);
}

int winnercheck(char board[3][3], char letter, int *won)
{
    if(board[0][0] == letter && board[1][0] == letter && board[2][0] == letter) *won=1;
    if(board[0][1] == letter && board[1][1] == letter && board[2][1] == letter) *won=1;
    if(board[0][2] == letter && board[1][2] == letter && board[2][2] == letter) *won=1;
    if(board[0][0] == letter && board[0][1] == letter && board[0][2] == letter) *won=1;
    if(board[1][0] == letter && board[1][1] == letter && board[1][2] == letter) *won=1;
    if(board[2][0] == letter && board[2][1] == letter && board[2][2] == letter) *won=1;
    if(board[0][0] == letter && board[1][1] == letter && board[2][2] == letter) *won=1;
    if(board[0][2] == letter && board[1][1] == letter && board[2][0] == letter) *won=1;
}

Any feedback appreciated! Thanks

Thanks for reply.

Incorrect initialization. Did you compile this code? And it gave you no warnings?

What do you mean by "incorrect initialization". Program works fine - complied in the CodeBlocks package if that's any help.

Unused variables. The X, O variables are unused.

For some reason, at the time I thought I would have to 'define' these.

Pointers instead of references.

References are later in the tutorials so I didn't know about them. I'll try and get them in!

Code duplication (why are you repeating the same thing twice?).

I'm assuming you're talking about the move function. I have the range and check bit before the while loop to check that the input is in the correct format. If it isn't it goes to the while loop. If they input the wrong thing again, it keeps on asking the person to put in the right input. Without the copied bit, the program will go ahead with the wrong inputs and mess up. The code is pretty inefficient I admit!

Use of an int (turn) instead of an enum.

What does the brackets around "turn" do? Where can I read up on it?

Cheers for help!

Thanks for feedback It's been helpful! I'll try and understand your program - looks pretty crazy though!
Scott