Problem with Tic Tac Toe Toggle

[Pegasus1]

Hello everyone,

I am trying to construct a really basic Tic Tac Toe game. There is something wrong with the toggle. After player X moves, it toggles to O. But after this first toggle it doesn't go back to X. What's the problem here? Also, are there any suggestions for how to optimize this code? (Ignore the part where it says "computer wins." I am planning to make this a player vs. computer Tic Tac Toe game, but I want to fix the Toggle problem first before coding that in). Thanks in advance!

#include <iostream>
#include <limits>
#ifdef __cplusplus__
  #include <cstdlib>
#else
  #include <stdlib.h>
#endif


using namespace std;

char grid[3][3] = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
char player = 'X';

void Draw()
{
    if (system("CLS")) system("clear");                         // clears the screen

    for(int r = 0; r < 3 ; ++r)
    {
       cout << "-----------"<< endl;
       for(int c = 0; c < 3; ++c)
       {
           cout << grid[r][c] << " | ";
       }
       cout << endl;
    }
}

void input()
{

    cout << endl;
    cout << "Input the number of the field you would like to fill." << endl;

    int n;
    LOOP: cin >> n;

    while(!cin || n < 1 || n > 9)                                       // disallows inputs that are not integers between 1 and 9.
    {
        cout << "Please enter an integer value between 1 and 9." << endl;
        cin.clear();
        cin.ignore(numeric_limits <streamsize>::max(), '\n');
        goto LOOP;
    }

    if(n == 1)
    {
        if(grid[0][0] == '1')
        {
            grid[0][0] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 2)
    {
        if(grid[0][1] == '2')
        {
            grid[0][1] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }

    else if(n == 3)
    {
        if(grid[0][2] == '3')
        {
            grid[0][2] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 4)
    {
        if(grid[1][0] == '4')
        {
            grid[1][0] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 5)
    {
        if(grid[1][1] == '5')
        {
            grid[1][1] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 6)
    {
        if(grid[1][2] == '6')
        {
            grid[1][2] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 7)
    {
        if(grid[2][0] == '7')
        {
           grid[2][0] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 8)
    {
        if(grid[2][1] == '8')
        {
            grid[2][1] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
    else if(n == 9)
    {
        if(grid[2][2] == '9')
        {
            grid[2][2] = player;
        }
        else
        {
            cout << "This field has already been taken; please try again!" << endl;
            input();
        }
    }
}
void TogglePlayer()
{
    if(player = 'X')
    {
        player = 'O';
    }
    else if(player = 'O')
    {
        player = 'X';
    }
}
char Win()
{

/*

Grid Field:

00 | 01 | 02
------------
10 | 11 | 12
------------
20 | 21 | 22

*/
    // Checking to see if we have three 'X's in a row

    if(grid[0][0] == 'X' && grid[0][1] == 'X' && grid[0][2] == 'X')
    {
        return 'X';
    }
    if(grid[1][0] == 'X' && grid[1][1] == 'X' && grid[1][2] == 'X')
    {
        return 'X';
    }
    if(grid[2][0] == 'X' && grid[2][1] == 'X' && grid[2][2] == 'X')
    {
        return 'X';
    }

    //Checking to see if we have three 'X's in a column

    if(grid[0][0] == 'X' && grid[1][0] == 'X' && grid[2][0] == 'X')
    {
        return 'X';
    }
    if(grid[0][1] == 'X' && grid[1][1] == 'X' && grid[2][1] == 'X')
    {
        return 'X';
    }
    if(grid[0][2] == 'X' && grid[1][2] == 'X' && grid[2][2] == 'X')
    {
        return 'X';
    }

    //Checking to see if we have three 'X's in a diagonal

    if(grid[0][0] == 'X' && grid[1][1] == 'X' && grid[2][2] == 'X')
    {
        return 'X';
    }
    if(grid[2][0] == 'X' && grid[1][1] == 'X' && grid[0][2] == 'X')
    {
        return 'X';
    }

    //Checking to see if we have three 'O's in a row

    if(grid[0][0] == 'O' && grid[0][1] == 'O' && grid[0][2] == 'O')
    {
        return 'O';
    }
    if(grid[1][0] == 'O' && grid[1][1] == 'O' && grid[1][2] == 'O')
    {
        return 'O';
    }
    if(grid[2][0] == 'O' && grid[2][1] == 'O' && grid[2][2] == 'O')
    {
        return 'O';
    }

    //Checking to see if we have three 'O's in a column

    if(grid[0][0] == 'O' && grid[1][0] == 'O' && grid[2][0] == 'O')
    {
        return 'O';
    }
    if(grid[0][1] == 'O' && grid[1][1] == 'O' && grid[2][1] == 'O')
    {
        return 'O';
    }
    if(grid[0][2] == 'O' && grid[1][2] == 'O' && grid[2][2] == 'O')
    {
        return 'O';
    }

    //Checking to see if we have three 'O's in a diagonal

    if(grid[0][0] == 'O' && grid[1][1] == 'O' && grid[2][2] == 'O')
    {
        return 'O';
    }
    if(grid[2][0] == 'O' && grid[1][1] == 'O' && grid[0][2] == 'O')
    {
        return 'O';
    }
}
int main()
{
    int count = 0;
    cout << "Welcome to the Tic Tac Toe Game!" << endl; cout << endl;
    Draw();
    while (count < 9)
    {
        ++count;
        input();
        Draw();

        if (Win() == 'X')
        {
            cout << "You win!" << endl;
            break;
        }
        else if (Win() == '0')
        {
            cout << "The computer wins!" << endl;
            break;
        }
        else if (Win() != 'X' && Win() != 'X' && count == 8)
        {
            cout << "You drew with the computer!" << endl;
        }
        TogglePlayer();
    }
    if(count == 9)
    {
        cout << endl; cout << "Game over!" << endl;
    }
}

[Yanson]

if(player = 'X') this is assignment not equality. It should look more like this
if(player == 'X')