tic-tac-toe.c File Reference

Tic-Tac-Toe game implementation in C More...

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

Include dependency graph for tic-tac-toe.c:

Functions
static void	singlemode ()
	Implementation of game vs computer. More...
static void	doublemode ()
	Implementation of game vs another player. More...
static void	placex (int m)
	Update table by placing an X More...
static void	place ()
	Update table by placing an O More...
static void	placey (int e1)
	Update table by placing an O More...
int	checkwin ()
	Implementation of win conditon checker for 'X' or 'O' whenever the table is updated. More...
int	main ()
	Main program function. More...

Variables
static char	game_table [9]
	Tic-Tac-Toe table, so basically we are using variable 'game_table' as the table(size:3X3) and updating it regularly.

Detailed Description

Tic-Tac-Toe game implementation in C

Author

vivekboss99

Krishna Vedala

Tic-Tac-Toe Game,where the user can decide to play with the computer(single player mode) or with other user(double player mode) , the code as an array named 'game_table' which is the table and user needs to enter the position inside the array(from 1-9) where he/she wants to place 'X' or 'O' on the table.

Function Documentation

checkwin()

int checkwin

(

)

Implementation of win conditon checker for 'X' or 'O' whenever the table is updated.

Returns

-1: if 'X' won

-2: if 'O' won

0: if there is no win condition for 'X' or 'O'

{
    if (game_table[0] == game_table[1] && game_table[1] == game_table[2])
    {
        if (game_table[0] == 'x' && game_table[1] == 'x' &&
            game_table[2] == 'x')
        {
            return -1;
        }
 
        if (game_table[0] == 'o' && game_table[1] == 'o' &&
            game_table[2] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[0] == game_table[4] && game_table[4] == game_table[8])
    {
        if (game_table[0] == 'x' && game_table[4] == 'x' &&
            game_table[8] == 'x')
        {
            return -1;
        }
 
        if (game_table[0] == 'o' && game_table[4] == 'o' &&
            game_table[8] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[0] == game_table[3] && game_table[3] == game_table[6])
    {
        if (game_table[0] == 'x' && game_table[3] == 'x' &&
            game_table[6] == 'x')
        {
            return -1;
        }
 
        if (game_table[0] == 'o' && game_table[3] == 'o' &&
            game_table[6] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[3] == game_table[4] && game_table[4] == game_table[5])
    {
        if (game_table[3] == 'x' && game_table[4] == 'x' &&
            game_table[5] == 'x')
        {
            return -1;
        }
 
        if (game_table[3] == 'o' && game_table[4] == 'o' &&
            game_table[5] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[6] == game_table[7] && game_table[7] == game_table[8])
    {
        if (game_table[6] == 'x' && game_table[7] == 'x' &&
            game_table[8] == 'x')
        {
            return -1;
        }
 
        if (game_table[6] == 'o' && game_table[7] == 'o' &&
            game_table[8] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[1] == game_table[4] && game_table[4] == game_table[7])
    {
        if (game_table[1] == 'x' && game_table[4] == 'x' &&
            game_table[7] == 'x')
        {
            return -1;
        }
 
        if (game_table[1] == 'o' && game_table[4] == 'o' &&
            game_table[7] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[2] == game_table[5] && game_table[5] == game_table[8])
    {
        if (game_table[2] == 'x' && game_table[5] == 'x' &&
            game_table[8] == 'x')
        {
            return -1;
        }
 
        if (game_table[2] == 'o' && game_table[5] == 'o' &&
            game_table[8] == 'o')
        {
            return -2;
        }
    }
    else if (game_table[2] == game_table[4] && game_table[4] == game_table[6])
    {
        if (game_table[2] == 'x' && game_table[4] == 'x' &&
            game_table[6] == 'x')
        {
            return -1;
        }
 
        if (game_table[2] == 'o' && game_table[4] == 'o' &&
            game_table[6] == 'o')
        {
            return -2;
        }
    }
    return 0;
}

doublemode()

void doublemode ( )

static

Implementation of game vs another player.

Returns

None

{
    int m;
    int e1;
    int k = 0;
    int doublemode_table_count=0;
 
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            printf("%c ", game_table[k]);
            k++;
        }
 
        printf("\n");
    }
    for (int x = 1; x < 10; x++)
    {
        k = 0;
 
        printf("PLAYER1 - where would you like to place 'x' : ");
        scanf("%d", &m);
 
        placex(m);
        if(doublemode_table_count<4)
        {
        printf("PLAYER2 - where would you like to place 'o' : ");
        scanf("%d", &e1);
 
        placey(e1);
        }
 
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                printf("%c ", game_table[k]);
                k++;
            }
 
            printf("\n");
        }
        doublemode_table_count++;
        int o = checkwin();
 
        if (o == -1 || o == -2)
        {
            if (o == -1)
            {
                printf("Player 1 WIN\n");
            }
            if (o == -2)
            {
                printf("Player 2 WIN\n");
            }
 
            break;
        }
        if (doublemode_table_count==4)
        {
            printf("\nDRAW ");
            break;
        }
    }
}

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main()

int main

(

)

Main program function.

Returns

0 on clean exit.

Note

No checks are included for program execution failures!

{   srand(time(NULL));
    int l = 0;
    do
    {
        int n = 0;
 
        // filling the table with multiple asterisks
        for (int i = 0; i < 9; i++) game_table[i] = '*';
 
        // displaying the main menu
        printf("***************************************\n");
        printf("*************TIC TAC TOE***************\n");
        printf("***************************************\n");
        printf("***********1. YOU vs COMPUTER ***********\n");
        printf("***********2. YOU vs PLAYER ***********\n");
        printf("***********3.EXIT *********************\n");
        printf("Enter your choice : ");
        scanf("%d", &n);
 
        switch (n)  // switch case to select between single player mode or
                    // double player mode
        {
        case 1:
            singlemode();
            break;
        case 2:
            doublemode();
            break;
        default:
            printf("THANK YOU and EXIT!");
        }
 
        printf("Next game ? : ");
        printf("Enter 1 – YES and 0 - NO ");
        scanf("%d", &l);
 
    } while (l == 1);
 
    return 0;
}

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place()

void place ( )

static

Update table by placing an O

Returns

None

{
 
    int e = rand() % 9;
 
    if (e >= 0 && e <= 8)
    {
        if (game_table[e] != 'x' && game_table[e] != 'o')
        {
            game_table[e] = 'o';
            printf("\n Computer placed at %d position\n", e + 1);
        }
        else
        {
            place();
        }
    }
}

placex()

void placex ( int  m )

static

Update table by placing an X

Parameters

m	location to place X

Returns

None

{
    int n1;
    if (m >= 1 && m <= 9)
    {
        if (game_table[m - 1] != 'x' && game_table[m - 1] != 'o')
        {
            game_table[m - 1] = 'x';
        }
        else
        {
            printf("Invalid move\n");
 
            printf("Enter new position : ");
            scanf("%d", &n1);
 
            placex(n1);
        }
    }
    else
    {
        printf("Invalid move \n");
 
        printf("Enter new position : ");
        scanf("%d", &n1);
 
        placex(n1);
    }
}

placey()

void placey ( int  e1 )

static

Update table by placing an O

Parameters

e1	location to place O

Returns

None

{
    int n1;
    if (e1 >= 1 && e1 <= 9)
    {
        if (game_table[e1 - 1] != 'x' && game_table[e1 - 1] != 'o')
        {
            game_table[e1 - 1] = 'o';
        }
        else
        {
            printf("Invalid move \n");
 
            printf("Enter new position : ");
            scanf("%d", &n1);
 
            placey(n1);
        }
    }
    else
    {
        printf("Invalid move \n");
 
        printf("Enter new position : ");
        scanf("%d", &n1);
 
        placey(n1);
    }
}

singlemode()

void singlemode ( )

static

Implementation of game vs computer.

Returns

None

{
    int m;
    int k = 0;
    int table_fill_count=0;
 
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            printf("%c ", game_table[k]);
            k++;
        }
 
        printf("\n");
    }
 
    for (int x = 1; x < 10; x++)
    {
        k = 0;
 
        printf("Where would you like to place 'x' ");
        scanf("%d", &m);
 
        placex(m);
        if(table_fill_count<4)
        {
          place();
        }
 
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                printf("%c ", game_table[k]);
                k++;
 
            }
 
            printf("\n");
        }
        table_fill_count++;
        int o = checkwin();
 
        if (o == -1 || o == -2)
        {
            if (o == -1)
            {
                printf("YOU WIN\n");
            }
            if (o == -2)
            {
                printf("YOU LOSE\n");
            }
 
            break;
        }
 
        if (table_fill_count==4)
        {
            printf("\nDRAW ");
            break;
        }
    }
}

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