Help needed with Othello game program

[sanjusingh]

Hello,
I am new to C++ and trying to create an Othello game. My human player function is looping but it does not work for my computer player. I tried to solve but still stuck and not getting where is the mistake. Any help would be grateful. Here is the code I have so far.

#include <iostream>
#include <string>
#include <ctime>
using namespace std;

const int SIZE = 8;
const char HUMAN_PLAYER = 'b';
const char COMPUTER_PLAYER = 'w';


//Display the board
void displayBoard(char board[][SIZE]){
	cout << endl;
	cout << "    ";
	for(int col = 0; col < SIZE; col++){
		cout << (char)('a' + col) << "    ";
	}

	cout << endl;
	for(int row = 0; row < SIZE; row++)
	{
		cout << "   ";
		for(int col = 0; col < SIZE; col++)
		{
			cout << ("-----");
		}
		cout << endl;
		cout << row + 1 << "  ";

		for(int col = 0; col < SIZE; col++)
		{
			cout << ("| ");

			if(board[row][col] == ' ')
				cout << "   ";
			else
				cout << board[row][col] << " ";
		}
		cout << "|" << endl;
	}

	cout << "   ";

	for(int col = 0; col < SIZE; col++)
	{
			cout << "-----";
	}

	cout << endl;
	cout << endl;
}

int moveIsPossible(char board[][SIZE], char player){
	return 1;
}

/*Place the discs on the board and make appropriate flips. After making appropriate
 *flips return the number of discs flipped
 */
int placeDisc(char board[][SIZE], int row, int col, char disc){
	int discFlipped = 0;

	if(board[row][col] != ' ')
		return 0;

	board[row][col] = disc;

	char opponentDisc;
	if(disc == HUMAN_PLAYER)
		opponentDisc = COMPUTER_PLAYER;
	else
		opponentDisc = HUMAN_PLAYER;

	//Check are there discs on the right side to flip
	int disc_pos = -1;
	for(int c = col + 1; c < SIZE && board[row][c] != ' ' && disc_pos == -1; c++)
	{
		if(board[row][c] == disc)
			disc_pos = c;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 && disc_pos > col + 1)
	{
		for(int c = col + 1; c < disc_pos; c++ )
		{
			board[row][c] = disc;
			discFlipped++;
		}
	}

	//Check are there discs on the left side to flip
	disc_pos = -1;
	for(int c = col - 1; c >= 0 && board[row][c] != ' ' && disc_pos == -1; c--)
	{
		if(board[row][c] == disc)
			disc_pos = c;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 && disc_pos < col - 1)
	{
		//Flip the discs to the left
		for(int c = col - 1; c > disc_pos; c-- )
		{
			board[row][c] = disc;
			discFlipped++;
		}
	}

	//Check are there discs above to flip
	disc_pos = -1;
	for(int r = row - 1; r >= 0 && board[r][col] != ' ' && disc_pos == -1; r--)
	{
		if(board[r][col] == disc)
			disc_pos = r;
	}

	if(disc_pos != -1 && disc_pos < row - 1)
	{
		//Flip discs above
		for(int r = row - 1; r > disc_pos; r--)
		{
			board[r][col] = disc;
			discFlipped++;
		}
	}

	//Check are there discs below to flip
	disc_pos = -1;
	for(int r = row + 1; r < SIZE && board[r][col] != ' ' && disc_pos == -1; r++)
	{
		if(board[r][col] == disc)
			disc_pos = r;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 && disc_pos > row + 1)
	{
		//Flip discs below
		for(int r = row + 1; r < disc_pos; r++ )
		{
			board[r][col] = disc;
			discFlipped++;
		}
	}

	//Check are there discs on diagnally upper left side to flip
	disc_pos = -1;
	int c = col - 1;
	for(int r = row - 1; c >= 0 && r >= 0 && board[r][c] != ' ' && disc_pos == -1; r-- )
	{
		if(board[r][c] == disc)
			disc_pos = r;
		c--;
	}

	//Make sure we found a disc and it is atleast 2 spots away
		if(disc_pos != -1 && disc_pos < row - 1)
		{
			c = col -1;
			for(int r = row - 1; r > disc_pos; r--)
			{
				board[r][c] = disc;
				discFlipped++;
				c--;
			}
		}

	//Check are there discs on diagnally upper right side to flip
	disc_pos = -1;
	c = col + 1;
	for(int r = row - 1; c < SIZE && r >=0 && board[r][c] != ' ' && disc_pos == -1; r--)
	{
		if(board[r][c] == disc)
			disc_pos = r;
		c++;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 &&  disc_pos < row - 1)
	{
		c =  col + 1;
		for(int r = row - 1; r > disc_pos; r--)
		{
			board[r][c] = disc;
			discFlipped++;
			c++;
		}
	}

	//Check are there discs on diagnally lower left side to flip
	disc_pos = -1;
	c = col - 1;
	for(int r = row + 1; c >= 0 && r < SIZE && board[r][c] != ' ' && disc_pos == -1; r++)
	{
		if(board[r][c] == disc)
			disc_pos = r;
		c--;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 && disc_pos > row + 1)
	{
		c = col - 1;
		for(int r = row + 1; r < disc_pos; r++)
		{
			board[r][c] = disc;
			discFlipped++;
			c++;
		}
	}

	//Check are there discs on diagnally lower right side to flip
	disc_pos = -1;
	c = col + 1;
	for(int r = row + 1; c < SIZE && board[r][c] != ' ' && disc_pos == -1; r++)
	{
		if(board[r][c] == disc)
			disc_pos = r;
		c++;
	}

	//Make sure we found a disc and it is atleast 2 spots away
	if(disc_pos != -1 && disc_pos > row + 1)
	{
		c = col + 1;
		for(int r = row + 1; r < disc_pos; r++)
		{
			board[r][c] = disc;
			discFlipped++;
			c++;
		}
	}

	//Reset the board if no flip or illegal move is played
	if(discFlipped == 0)
		board[row][col] = ' ';

	return discFlipped;

}

void getHumanMove(char board[][SIZE]){
  int row, col;
  bool isIllegalMove;

  /*cout << "You are player 'b' & computer is 'w'" << endl;
  cout << "Input row and column between 0 to 8" << endl;
  cout <<"\n";*/
  
  do 
  {
    do
    {
      isIllegalMove = false;
      cout << "Enter the row you want to make a move to: ";
      cin >> row;

      while(row < 0 || row >= SIZE){
	cout << "Please enter a valid row between 0 and  " << (SIZE - 1) <<     
        endl;
        cout << "Enter the row you want to make move to: ";
	cin >> row;
      }

      cout << "Enter the column you want to make a move to: ";
      cin >> col;
      while(col < 0 || col >= SIZE){
	cout << "Please enter a valid column between 0 and  " << (SIZE - 1) <<   
        endl;
	cout << "Enter the column you want to make a move to: ";
	cin >> col;
      }

      if(board[row][col] != ' '){
	cout << "\nPlease select an empty row and column to make a valid move" 
        << endl;
	isIllegalMove = true;
      } else{
	  int discsFlipped = placeDisc(board, row, col, HUMAN_PLAYER);
	  if(discsFlipped == 0){
	     cout << "Invalid move.\n" << endl;
	     isIllegalMove = true;
	  } 
          else if(discsFlipped == 1)
	     cout << "Flipped 1 disc.\n\n" << endl;
	  else
	     cout << "Flipped " << discsFlipped << " discs." << endl;
	}
    }while(isIllegalMove);
    cout << "\nUpdated board" << endl;
    displayBoard(board);
  } while(moveIsPossible(board, HUMAN_PLAYER));
	gameOver(board);
}

void getComputerMove(char board[][SIZE]){
  int row;
  int col;
  bool isIllegalMove;
  srand(time(0));

  int randomRow;
  int randomCol;

  if(moveIsPossible(board, COMPUTER_PLAYER))
  {
	do
	{	
           randomRow = rand() % 8;
	   randomCol = rand() % 8;

	   isIllegalMove = false;
	   row = randomRow;
	   col = randomCol;

	   if(row < 0 || row > SIZE){
		row = randomRow;
           }

	   cout << "\nComputer move details: " << endl;
	   cout << "Row: " << row;

	   if(col < 0 || col > SIZE){
		col = randomCol;
	   }
	   cout << ", Column: " << col;

	   if(board[row][col] != ' '){
		isIllegalMove = true;
	   }else{
	     int discsFlipped = placeDisc(board, row, col, COMPUTER_PLAYER);
	     if(discsFlipped == 0){
		cout << "\nInvalid move.\n" << endl;
		isIllegalMove = true;
	   }
	   else if(discsFlipped == 1)
	      cout << "\nFlipped 1 disc.\n\n" << endl;
	  else
	    cout << "\nFlipped " << discsFlipped << " discs." << endl;
	}
    }while(isIllegalMove);
		//displayBoard(board);
   }
}

void gameOver(char board[][SIZE]){
	cout << "\nGame is over. ";

	//Check result
	int countBlackDiscs = 0;
	int countWhiteDiscs = 0;
	for(int row = 0; row < SIZE; row++)
	{
		for(int col = 0; col < SIZE; col++)
		{
			if(board[row][col] == 'b')
				countBlackDiscs++;

			if(board[row][col] == 'w')
				countWhiteDiscs++;
		}
	}

	if(countBlackDiscs > countWhiteDiscs)
		cout << "Black won!" << endl;
	else if(countBlackDiscs < countWhiteDiscs)
		cout << "White won!" << endl;
	else
		cout << "It is a tie!" << endl;
}

int main(){
	char board[SIZE][SIZE];

	//Initialize the board
	for(int i = 0; i < SIZE; i++)
		for(int j = 0; j < SIZE; j++)
			board[i][j] = ' ';

	board[SIZE / 2 - 1][SIZE / 2 - 1] = 'w';
	board[SIZE / 2 - 1][SIZE / 2] = 'b';
	board[SIZE / 2][SIZE / 2  - 1] = 'b';
	board[SIZE / 2][SIZE / 2] = 'w';

	displayBoard(board);

	//Get human player's turn
	getHumanMove(board);

	//Get computer's turn
	getComputerMove(board);

	return 0;
}

[Zaap]

First, please use "code" format.

Second, what is the exact problem. What is the missfunctionning thing ? Crash ? Infinity loop ?

[sanjusingh]

Hello Zaap,
Thnx for the response and sorry about the format.
The getComputerMove function is having an infinite loop in between the game and is only working when it is being called inside the getHumanMove function. But it is not efficient to call the function inside the getHumanMove. When I am trying to call it in the main function it is not working(no output showing)

[lastchance]

Your code doesn't compile.

You are also looping inside getHumanMove until such time as a move becomes impossible. I doubt that it ever gets the chance to call getComputerMove.

Why is your indentation so inconsistent within the code?

[TightCoderEx]

Let's begin by cleaning up your code and hopefully making it easier to maintain and understand.

A: Simply functions as it's not necessary to pass the array. Make it global.
B: If your going to use constants, use them everywhere.

#include <iostream>
#include <string>
#include <ctime>

using namespace std;

const int SIZE = 8;
const char HUMAN = 'B';
const char COMPUTER = 'W';

    char board[SIZE][SIZE];

//Display the board
void displayBoard() {
    char  ch = 'A';
    string line (SIZE*4+1, '-'); // To accommodate different board sizes

    // Display column heading
    cout << "\t\t\t  ";    
    for (int col = 0; col < SIZE; col++)
        cout << "  " << ch++ << " ";        
    cout << "\n\t\t\t  " << line << "-";
    
    // Display each row with initial play pieces.
    for (int row = 0; row < SIZE; row++) {
        cout << "\n\t\t     " << setw(3) << row + 1 << "  ";
        for (int col = 0; col <= SIZE; col++)
            cout << "| " << board[row][col] << " ";
        cout << "\n\t\t\t  " << line << "-";
    }         
}

int main(){
    // VTIOO emulation on Gnome terminal LINUX
    cout << "\033[2J"; // Clear screen
    cout << "\033[8H"; // Set cursor to line 8
    
    //Initialize the board
    for(int i = 0; i < SIZE; i++)
        for(int j = 0; j < SIZE; j++)
            board[i][j] = ' ';

    int center = SIZE / 2;
    
    board[center - 1][center - 1] = COMPUTER;
    board[center - 1][center] = HUMAN;
    board[center][center  - 1] = HUMAN;
    board[center][center] = COMPUTER;

    displayBoard();

    cout << "\033[44H"; // Set cursor to line 44
    return EXIT_SUCCESS;
}

Would you agree the output looks a lot cleaner now. Now I'll begin working on other elements.

     A   B   C   D   E   F   G   H 
  -----------------------------------
1  |   |   |   |   |   |   |   |   |   
  -----------------------------------
2  |   |   |   |   |   |   |   |   |   
  -----------------------------------
3  |   |   |   |   |   |   |   |   |   
  -----------------------------------
4  |   |   |   | W | B |   |   |   |   
  -----------------------------------
5  |   |   |   | B | W |   |   |   |   
  -----------------------------------
6  |   |   |   |   |   |   |   |   |   
  -----------------------------------
7  |   |   |   |   |   |   |   |   |   
  -----------------------------------
8  |   |   |   |   |   |   |   |   |  
  -----------------------------------

NOTE: I'm going to be using cursor positioning using VT100, but if you don't have that it's just a simple matter of calling displayBoard () every time a move is made.

[sanjusingh]

Hello lastchance,
Oh but its compiling on eclipse. Actually I am looping as it is an ethello game. Is this not the correct way to do it?

[sanjusingh]

Hello TightCoderEx,
Thank you. Yes please and I do agree the code looks more cleaner :-)

[lastchance]

@sanjusingh,
Press the little gear wheel icon to the top right of your original code sample. It will attempt to compile the code ... and fail.

Are you sure that you are referring to the same code as you have posted?

On line 295 you (attempt to) call gameOver() at the end of getHumanMove(). Is that not an attempt to end the game before the non-human has a chance to go? Looking at the indentation here, it appears to be a bit of a cut-and-paste afterthought.

[sanjusingh]

@lastchance,
No, actually I was testing thats why gameOver function is still there. I was testing for human player only thats why still there. Yes, but after deleting the gameOver function from line 295 only the human player function is looping not the computer player. Computer player is not working once also

[lastchance]

In the code you have given (which doesn't compile - try it) you end the main loop in getHumanMove() with
} while(moveIsPossible(board, HUMAN_PLAYER));
This last condition is always true because (in the code you have given) moveIsPossible() is just

int moveIsPossible(char board[][SIZE], char player){
	return 1;
}

and an int value of one will implicitly cast, when required, to boolean true. So you will loop indefinitely and not leave the getHumanMove routine.

Please supply COMPILEABLE code, turn your compiler warnings up so that you can see other anomalies, and tell us precisely what input gives what wrong output.

Having commented out the call on line 295 (to make the code compile) I tried running the code and discovered that your columns are headed by letters (chars) but you presumably want to input an int. That is far from obvious. For those of us who haven't played Othello in a long time, what input would you like?