Thread: tic tac toe check winner

i'm creating a tic tac toe game (no functions unfortunately.....sorry!) and was trying to check for a winner at the end of each turn. Is there any way of doing this without using a hefty amount of "if" statements? I have already searched the forum but the only examples I could find included these statements in mass.

I was thinking to using a nested "for" loop but the problem came that I would only be searching row wins and column wins...i'm stumped. If you would like to see my code, see below. Like I said, there is no check yet, but I added a comment line so you can see where it would start.

Code:

//Tic Tac Toe
//Dustin Hardin 12-12-08

//Play the classic game of tic tac toe

#include <iostream>
#include <string>
#include <cstdlib>
#include <ctime>

using namespace std;

int main()
{
    const short NUM_ROWS = 3, NUM_COLUMNS = 3;
    const short unsigned MAX_PLAYERS = 2;
    short unsigned numPlayers, numComputer, rowSelect, columnSelect, xCheck = 0, oCheck = 0;
    bool playerMove, gameBoardFull = true;
    short unsigned int whoFirst, whoWin = 0, move, playerCheck, opponentCheck;
    srand(time(0));
    
    string players[MAX_PLAYERS];
    
    string board[NUM_ROWS][NUM_COLUMNS] = 
    {
        {"|#|","|#|","|#|"},
        {"|#|","|#|","|#|"},
        {"|#|","|#|","|#|"}
    };
    
    
    while (true)  //Game Loop
    {   
        
        
        //get number of players
        do{
        system("cls");
        cout << "\t\tWelcome to Tic-Tac-Toe!\n\n";
        
        cout << "How many players will be joining us today? (1-2): ";
        cin >> numPlayers;
        cin.ignore();
        
        }while (numPlayers != 1 && numPlayers != 2);
        
        numComputer = 2 - numPlayers;
        
        //inform player of who is playing
        if (numPlayers == 1)
        {
           cout << "\nGreat! So there will be " << numPlayers << " Human Vs. " << numComputer << " Computer!\n\n";
           players[0] = "Player";
           players[1] = "Computer";
        }
        else
        {
            cout << "Great! So it will be Human Vs. Human!\n\n";
            players[0] = "Player 1";
            players[1] = "Player 2";
        }
        
        cin.get();
        
        
        //RULES!
        system("cls");
        cout << "\t\tRULES: \n\n";
        cout << "1.  You must pick a position to start in. (1-9)\n"
             << "the top row is 1-3, second 4-6, third 7-9" << endl;
        cout << "\n2.  Who goes 'first' is random....so no complaining!\n\n";
        cin.get();
        system("cls");
            
            
        //Display who is first    
        cout << "DECIDING WHO GOES FIRST...PLEASE WAIT.....";
        whoFirst = rand() % 2 + 1; //pick either one of the players to go first
        cin.get();
        
        if(whoFirst == 1)
        {
            playerMove = true;
            cout << "\n\n" << players[0] << " goes first";
            cin.get();
        }
        else
        {
            playerMove = false;
            cout << "\n\n" << players[1] << " goes first";
            cin.get();
        }

       system("cls"); 
        
        
        //now enter the game of tic-tac-toe
        do
        {   
            gameBoardFull = true;
            system("cls");
            
            //check to see if full board (draw)
             for(int j = 0; j < 3; j++)
             {
                     for(int k = 0; k < 3; k++)
                     {
                             if (board[j][k] == "|#|")
                             {
                                 gameBoardFull = false;
                             }
                     }
             }
            
            if(gameBoardFull == false)
            {
                //display board                              
                for(int i = 0; i < 3; i++)
                {
                        for(int j = 0; j < 3; j++)
                        {
                                cout << board[i][j];
                        }
                        cout << endl;
                }
                
                
                //check who's move it is and get input
                do
                {
                    if( playerMove == true)
                    {
                        cout << players[0] << ": ";
                        cin >> move;
                        cin.ignore();
                    }
                    else if(playerMove == false && numPlayers == 2)
                    {
                         cout << players[1] << ": ";
                         cin >> move;
                         cin.ignore();
                     }
                     else if(playerMove == false && numPlayers == 1)
                     {
                         move = rand() % 9 + 1;
                     }
                     
                 } while(move < 1 && move > 9);
                 
                 //adjust move to the corresponding row and columns
                 if (move > 0 && move < 4)
                 {
                      rowSelect = 0;
                      columnSelect = move - 1;
                 }
                 else if (move > 3 && move < 7)
                 {
                      rowSelect = 1;
                      columnSelect = move - 4;
                 }
                 else if (move > 6 && move < 10)
                 {
                      rowSelect = 2;
                      columnSelect = move - 7;
                 }
     
                 if(board[rowSelect][columnSelect] == "|#|")
                 {
                 //place the marker on board
                     if (playerMove == true)
                     {
                        board[rowSelect][columnSelect] = "|X|";
                        playerMove = false;
                     }
                     else if (playerMove == false && numPlayers == 2)
                     {
                        board[rowSelect][columnSelect] = "|O|";
                        playerMove = true;
                        cin.get();
                     }
                     else
                     {
                         board[rowSelect][columnSelect] = "|O|";
                         playerMove = true;
                         cout << players[1] << ": " << move;   
                         cin.get();                       
                     }
                  }
              }
              
              //check for winner
              for(int i = 0; i < 3; i++)
              {
                            for(int j = 0; j < 3; j++)
                            {
                            }
              }

        }while(gameBoardFull == false);//add whoWin == 0 so that it will check for winner before end loop
        
        system("cls");
        
        if(gameBoardFull == true)
            cout << "\t\tGame Ended in Draw!";
        cin.get();
        break;
        
    }
    cin.get();
    
}

Once again, I'm very sorry about the lack of functions, I am trying to go step by step in my book and every chapter I try to make a game out of what I've learned so far (and very limited, yes).


Thanks again!

well, I did more searching...and it looks like everyone I looked at (which I gave up quickly) used a series of if statements. Not that I do not like using them, its just that I was hoping for a different way of checking for a winner. I will still be looking for answers, but in the mean time, I will code the if statements in and finish the game.

thanks again!

You can roll it into a single if statement that checks all 6 cases.

Or you can use a bit mask in a for loop.
or you can enumerate all winning boards into an array that contains the winner.

or ...

Code:

char Board[9]; // X = 1, O = 2, blank = 0

int winner = 
Board[0] * (Board[0] == Board[1] && Board[0] == Board[2]) +
Board[0] * (Board[0] == Board[3] && Board[0] == Board[6]) +
Board[0] * (Board[0] == Board[4] && Board[0] == Board[8]) +
Board[1] * (Board[1] == Board[4] && Board[1] == Board[7]) +
Board[2] * (Board[2] == Board[5] && Board[2] == Board[8]) +
Board[2] * (Board[2] == Board[4] && Board[2] == Board[6]) +
Board[3] * (Board[3] == Board[4] && Board[3] == Board[5]) +
Board[6] * (Board[6] == Board[7] && Board[6] == Board[8]);

enjoy

Originally Posted by Elysia

SourceForge.net: Void main - cpwiki

void main() is not improper, stop saying that it is. It may be improper for PC based applications, but PC's are hardly the only, or even the biggest, place C/C++ are used.

okay, thanks a lot for all who replied! I will be taking a look at my code and try to add in your advice (stuff that I understand more of course). Will post my code when i'm done.

thanks again!