Program: Tic Tac Toe Game

Introduction

In this section, we'll create a simple console-based Tic Tac Toe game in C. Tic Tac Toe is a classic two-player game where the goal is to form a line of three of your symbols (either 'X' or 'O') horizontally, vertically, or diagonally on a 3x3 grid.

Algorithm

Initialize Board:
- Create a 3x3 matrix representing the Tic Tac Toe board.
- Initialize all cells with empty spaces.
Display Board:
- Display the current state of the board to the players.
Get Player Move:
- Ask the current player to input their move (row and column).
Validate Move:
- Check if the specified move is within the board boundaries.
- Verify that the selected cell is empty.
Update Board:
- If the move is valid, update the board with the current player's symbol.
Check for Win:
- Check if the current player has won horizontally, vertically, or diagonally.
- If a win is detected, declare the current player as the winner.
Check for Tie:
- Check if the board is full (all cells are filled) without a winner.
- If a tie is detected, declare the game as a tie.
Switch Player:
- Switch to the other player (from 'X' to 'O' or vice versa).
Repeat:
- Repeat steps 2-8 until a win or a tie is achieved.

Pseudocode

function initializeBoard():
    for each row in board:
        for each cell in row:
            cell = ' '

function displayBoard():
    print("  0 1 2")
    for i from 0 to 2:
        print(i, end=" ")
        for j from 0 to 2:
            print(board[i][j], end=" ")
        print()

function isMoveValid(row, col):
    return (0 <= row < 3) and (0 <= col < 3) and (board[row][col] == ' ')

function checkForWin(player):
    for i from 0 to 2:
        if (board[i][0] == player and board[i][1] == player and board[i][2] == player) or
           (board[0][i] == player and board[1][i] == player and board[2][i] == player):
            return true

    if (board[0][0] == player and board[1][1] == player and board[2][2] == player) or
       (board[0][2] == player and board[1][1] == player and board[2][0] == player):
        return true

    return false

function isBoardFull():
    for each row in board:
        for each cell in row:
            if cell is empty:
                return false
    return true

function main():
    initializeBoard()
    currentPlayer = 'X'

    repeat:
        displayBoard()

        print("Player", currentPlayer + ",", "enter your move (row and column): ")
        row, col = getUserInput()

        if isMoveValid(row, col):
            board[row][col] = currentPlayer

            if checkForWin(currentPlayer):
                displayBoard()
                print("Player", currentPlayer, "wins!")
                break

            if isBoardFull():
                displayBoard()
                print("The game is a tie!")
                break

            currentPlayer = switchPlayer(currentPlayer)
        else:
            print("Invalid move. Try again.")

    end repeat

This pseudocode outlines the key steps of the Tic Tac Toe game, providing a structured guide for the implementation in C. Feel free to use this as a reference when coding the actual program.

Program Structure

1. Header Files

#include <stdio.h>
#include <stdlib.h>

2. Constants

#define SIZE 3

Define constants for the board size.

3. Function Declarations

void initializeBoard(char board[SIZE][SIZE]);
void displayBoard(char board[SIZE][SIZE]);
int isMoveValid(int row, int col, char board[SIZE][SIZE]);
int isBoardFull(char board[SIZE][SIZE]);
int checkForWin(char board[SIZE][SIZE], char player);

4. Main Function

int main() {
    char board[SIZE][SIZE];
    char currentPlayer = 'X';
    int row, col;

    initializeBoard(board);

    do {
        displayBoard(board);

        printf("Player %c, enter your move (row and column): ", currentPlayer);
        scanf("%d %d", &row, &col);

        if (isMoveValid(row, col, board)) {
            board[row][col] = currentPlayer;

            if (checkForWin(board, currentPlayer)) {
                displayBoard(board);
                printf("Player %c wins!\n", currentPlayer);
                break;
            }

            if (isBoardFull(board)) {
                displayBoard(board);
                printf("The game is a tie!\n");
                break;
            }

            currentPlayer = (currentPlayer == 'X') ? 'O' : 'X';
        } else {
            printf("Invalid move. Try again.\n");
        }
    } while (1);

    return 0;
}

5. Function Definitions

initializeBoard

void initializeBoard(char board[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            board[i][j] = ' ';
        }
    }
}

displayBoard

void displayBoard(char board[SIZE][SIZE]) {
    printf("\n  ");
    for (int i = 0; i < SIZE; i++) {
        printf("%d ", i);
    }
    printf("\n");

    for (int i = 0; i < SIZE; i++) {
        printf("%d ", i);
        for (int j = 0; j < SIZE; j++) {
            printf("%c ", board[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

isMoveValid

int isMoveValid(int row, int col, char board[SIZE][SIZE]) {
    return (row >= 0 && row < SIZE && col >= 0 && col < SIZE && board[row][col] == ' ');
}

isBoardFull

int isBoardFull(char board[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            if (board[i][j] == ' ') {
                return 0;
            }
        }
    }
    return 1;
}

checkForWin

int checkForWin(char board[SIZE][SIZE], char player) {
    for (int i = 0; i < SIZE; i++) {
        if ((board[i][0] == player && board[i][1] == player && board[i][2] == player) ||
            (board[0][i] == player && board[1][i] == player && board[2][i] == player)) {
            return 1;
        }
    }

    if ((board[0][0] == player && board[1][1] == player && board[2][2] == player) ||
        (board[0][2] == player && board[1][1] == player && board[2][0] == player)) {
        return 1;
    }

    return 0;
}

Conclusion

This enhanced Tic Tac Toe program provides a clearer structure and includes pseudocode for key functions. Feel free to explore additional features and improvements. If you have specific questions or if there are additional topics you'd like to explore, feel free to ask!

Last modified: 25 February 2024