Object oriented tic tac toe.

tictactoe.cpp

// 2023 Jibril Wathon
// github.com/etherealxx
// Public Domain

#include <iostream>
#include <vector>

using namespace std;

class TicTacToeBoard {
    public:
    int getSquareValueFromNumber(int squareNumber){
        // from left to right, top to bottom, 1 to 9
        return squareValues[(squareNumber - 1)]; // because of zero index
    }

    // check the owner of a square, and display the mark if any
    char chr(int squareNumber){
        int squareValue = getSquareValueFromNumber(squareNumber);
        string temp;
        switch(squareValue){
            case 0:
                // display the square number if there's no mark
                temp = to_string(squareNumber);
                break;
            case 1:
                temp = "@"; // First player own this square
                break;
            case 2:
                temp = "#"; // Second player own this square    
                break;
        };
        auto printedchar = temp.c_str()[0];
        return printedchar;
    }

    bool isGameOver(){
        if (winningState || drawState) return true;
        else false;
    }

    void placeMark(int squareNumber){
        int squareValue = getSquareValueFromNumber(squareNumber);
        if (squareValue == 0){
            // the selected square is now marked by the current player
            squareValues[(squareNumber - 1)] = playerID; 
            playerID = (playerID == 1) ? 2 : 1; // toggle between player 1 and 2
            failedMove = false;
        } else { // placing mark on occupied square
            failedMove = true;
        }
    }

    void checkLine(int firstSquare, int secondSquare, int thirdSquare){
        if (!winningState) {
            int square1st_val = getSquareValueFromNumber(firstSquare);
            int square2nd_val = getSquareValueFromNumber(secondSquare);
            int square3rd_val = getSquareValueFromNumber(thirdSquare);
            if (square1st_val == square2nd_val
                && square2nd_val == square3rd_val
                && (square1st_val +square2nd_val + square3rd_val) != 0){ // it's not an empty row
                    winningState = true;
                    winningSquares = {firstSquare, secondSquare, thirdSquare};
            }
        }
    }

    void checkWinner(){
        checkLine(1,2,3); // top row
        checkLine(4,5,6); // middle row
        checkLine(7,8,9); // bottom row

        checkLine(1,4,7); // left column
        checkLine(2,5,8); // middle column
        checkLine(3,6,9); // right column

        checkLine(1,5,9); // diagonal top-left to bottom-right
        checkLine(3,5,7); // diagonal top-right to bottom-left
    }

    void checkDraw(){
        if (!winningState){
            int checkDraw = 1;
            for (int v: squareValues) { // iterate on every square
                // draw in tictactoe will happen if the board is full but no line
                // if one of the square isn't marked, then the board is not full
                if (v == 0){
                    checkDraw = 0;
                    break;
                }
            }
            if (checkDraw == 1) drawState = true;
        }
    }

    void printWinner(){
        if (winningState){
            cout << endl << "Player " << ((playerID == 1) ? 2 : 1)
            << " is the winner!" << endl;
            printf("A straight line at square %d, %d, and %d!\n",
            winningSquares[0], winningSquares[1], winningSquares[2]);
        } else if (drawState){
            cout << endl << "No more space left, it's a draw!" << endl << endl;
        }
    }

    void printCheckPlayer(){
        cout << "Currently it's Player " << playerID << " turn!" << endl;
    }

    void printAdditionalInfo(){
        if (failedMove){
            cout << "That space is already occupied, choose another!" << endl;
            failedMove = false;
        }
    }

    void printBoard(){
        cout << "||||   ||   ||   ||   ||||" << endl;
        printf("||||   %c    %c    %c    ||||\n", chr(1), chr(2), chr(3));
        printf("||||   %c    %c    %c    ||||\n", chr(4), chr(5), chr(6));
        printf("||||   %c    %c    %c    ||||\n", chr(7), chr(8), chr(9));
        cout << "||||   ||   ||   ||   ||||" << endl;
    }

    private:
    int playerID = 1;
    bool failedMove = false;
    bool winningState = false;
    bool drawState = false;

    // the number is player who marked the square currently
    // 1 for player 1 (@), 2 for player 2 (#)
    // 0 means no one marked the square yet
    vector<int> squareValues = {0,0,0,0,0,0,0,0,0};
    // list of squares that make a line for the winner
    vector<int> winningSquares = {0,0,0};
};

int main(){
    int markNumber;
    TicTacToeBoard board;
    while (1 > 0) { // infinite loop
        system("cls"); // clearing the console
        cout << "Ether's TicTacToe" << endl << endl;
        cout << "Player 1: @   /   Player 2: #" << endl << endl;
        board.printBoard();
        if (!board.isGameOver()) {
            board.printCheckPlayer();
            board.printAdditionalInfo(); // tell if the player fails to mark before
            cout << "Type a number to put your mark there: ";
            cin >> markNumber;
            board.placeMark(markNumber);
            board.checkWinner();
            board.checkDraw();
        } else {
            board.printWinner();
            break;
        }
    }
}