Tic Tac Toe program in C++ for CS211 Spring 2025

Max Davy

Program Overview

• The board is stored as an array of integers with length 9. Each integer can be zero (empty space), 1 (player 1 space), or 2 (player 2 space)
• The board is visually displayed to the user with numbers 1 to 9 as placeholders for available spaces. On their turn, the player is prompted to enter the number of the space they want to play. If the player enters the number of a space that is already occupied, they are prompted to choose again until they choose correctly
• The game tracks the win condition by checking against a database of possible 3-in-a-row win configurations for each user. Upon one player winning, or the board being filled (i.e. a tie), the game announces the winner and prompts the player whether they want to continue playing or exit.

Program structure

main function

• Initializes the board array
• Loops until a win or tie:
  • Displays the board using the drawBoard function
  • Prompts Player 1 for their move
  • Checks that the move is valid using the ```validMove`` function
    • If move is invalid repeats until valid move is obtained
  • Saved the move
  • Draws the board using the drawBoard function
  • Checks for a winner using the winner function
    • If winner exits loop, else continues to player 2
  • Prompts Player 2 for their move
  • Checks that the move is valid using the ```validMove`` function
    • If move is invalid repeats until valid move is obtained
  • Saved the move
  • Draws the board using the drawBoard function
  • Checks for a winner using the winner function
• Prompts user for another game
  • Resets board if yes
  • Exits if no

announceWinner function

• Inputs:
  • Board array
  • Winner integer (see winner function)
• Function:
  • Displays winner to console
• Outputs:
  • None

validMove function

• Inputs:
  • Board array
  • Move square integer
• Function:
  • Checks that move square is within board range and empty
• Outputs:
  • Boolean whether move is valid

winner function

• Inputs:
  • Board array
• Function:
  • Checks if board is full
  • Checks against database of possible three-in-a line for each player
• Outputs:
  • Winner integer (1 for player 1, 2 for player 2, 3 for tie)

in function

• Inputs:
  • type - used for function overrides for different input types; type must be the same as desired input type, actual value does not matter
  • prompt string - will be displayed to console before getting input
  • cr boolean - see out function
• Function:
  • Displays prompt to console
  • Gets input from console
• Outputs:
  • user input

out function

• Inputs:
  • output - output to display to console; function overrides for different input types
  • cr - whether to output newline after prompt
• Function:
  • Displays output to console
• Outputs:
  • None