TTT

[vagabond11]

Hi, i'm running into 2 problems
1. I couldn't get it to change turn between user and ai.

2. I couldn't get it to check if user put in the same spot (line 93-100).

please help or any advice would be appreciate thank you.

// This program will allows the user to play tic-tac-toe against the computer.


#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;


// function Prototype.
void displayboard ();

void getusermove ();

void getcomputermove ();

int checkforwinner ();

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

int main ()
{
	int turn;

	for (turn = 1; checkforwinner() == 0 && turn < 9; turn++)
	{
		if (turn = 1)
		{
			getusermove ();
			turn = 2;
		}
		else 
		{
			getcomputermove ();
			turn = 1;
		}

	}

	// Display who win
    if (turn == 9 && !checkforwinner()) 
	{
      
      displayboard ();
      cout << " It a tie game! " << endl;
    
	} 
    
	if (checkforwinner() == 2) 
	{
      
      displayboard ();
      cout << " X wins!!! " << endl;
    
	} 
    
	if (checkforwinner() == 3) 
	{
      
      displayboard ();
      cout << " O wins!!! " << endl;

	}
		
	return 0;

}

// Display Board
void displayboard ()
{
	cout << endl;
	cout << board[0] << " | " << board[1] << " | " << board[2] << endl;
	cout << "---------" << endl;
	cout << board[3] << " | " << board[4] << " | " << board[5] << endl;
	cout << "---------" << endl;
	cout << board[6] << " | " << board[7] << " | " << board[8] << endl;
}


// Get x for user move.
void getusermove ()
{
	int move;

		displayboard ();
		cout << "Enter your move: ";
		cin >> move;

		move--;

		if (board[move] != 'x' || board[move] != 'o')
		{
			board[move] = 'x';
		}
		else
		{
			cout << "Invalid please reenter: ";
		}

}

// Get o for computer move.
void getcomputermove ()
{
	srand (unsigned int (time(NULL)));

	int move = rand() % 9;

		if (board[move] == ' ')
		{
			displayboard ();
			cout << "Computer is moving to: " << board[move];
		
			board[move] = 'o';
		}

}

// Winning conditions
int checkforwinner ()
{
	if (board[0] == board[1] && board[1] == board[2]) 
	{
		if (board[0] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[3] == board[4] && board[4] == board[5]) 
	{
		if (board[3] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[6] == board[7] && board[7] == board[8]) 
	{
		if (board[6] == 'x') 
		{
			return 2;
		} 
		else
		{
			return 3;
		}
	}
	if (board[0] == board[3] && board[3] == board[6])
	{
		if (board[0] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[1] == board[4] && board[4] == board[7]) 
	{
		if (board[1] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[2] == board[5] && board[5] == board[8]) 
	{
		if (board[2] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[0] == board[4] && board[4] == board[8]) 
	{
		if (board[0] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}
	if (board[2] == board[4] && board[4] == board[6]) 
	{
		if (board[2] == 'x') 
		{
			return 2;
		} 
		else 
		{
			return 3;
		}
	}

	return 0;

}

[ne555]

> I couldn't get it to change turn between user and ai.
if (turn = 1) compile with warnings

$ g++ -W{all,extra,pedantic} foo.cpp
foo.cpp: In function ‘int main()’:
foo.cpp:28:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
foo.cpp: In function ‘void getcomputermove()’:
foo.cpp:107:9: error: expected primary-expression before ‘unsigned’

== is comparison
= is assignment.

Also, it seems that your casting is incorrect. srand ( (unsigned int) (time(NULL)) );
However, you should initialize the random generator just one time in your program.

> I couldn't get it to check if user put in the same spot (line 93-100).
if (board[move] != 'x' || board[move] != 'o')
|| is or. && is and.
You can in fact write `or' `and' `not' there. http://www.cplusplus.com/reference/ciso646/
If already knew that, review your logic.

[AbstractionAnon]

if (board[move] != 'x' || board[move] != 'o')

That's not going to work the way you want it.
It's always going to return true.
You want an and condition.

if (board[move] != 'x' && board[move] != 'o')

[vagabond11]

Also, it seems that your casting is incorrect. srand ( (unsigned int) (time(NULL)) );
However, you should initialize the random generator just one time in your program.

should i put outside main or inside?

[ne555]

int main(){
   srand(42); //first line, done you've initialized the rng
//don't ever call that function again (unless you've got a good reason) 

[vagabond11]

cool, it work! but i still can't get it to change back to user turn after ai turn.

// Switch turn
	for (turn = 1; checkforwinner() == 0 && turn < 9; turn++)
	{
		if (turn == 1)
		{
			getusermove ();
		}
		else
		{
			getcomputermove ();
			turn = 1;
		}
	}

I also can't get ai not to pick the same #.

void getcomputermove ()
{
	int move = rand() %8 + 1;

		if (board[move] != 'x' && board[move] != 'o')
		{
			displayboard ();
			cout << "Computer is moving to: " << move;

			move--;
	
			board[move] = 'o';
		}
}

http://www.cplusplus.com/articles/EywTURfi/ it didn't say anything about how to pick different #.

[ne555]

> i still can't get it to change back to user turn after ai turn.
`turn++' would execute before checking the condition.
You assign it in line 11, and later increment it. So `turn' would be 2. (¿how would the loop terminate?)

for (turn = 1; checkforwinner() == 0 && turn < 9; turn++)
	if (turn%2 == 1)
		getusermove();
	else
		getcomputermove();

> I also can't get ai not to pick the same #.
Try again. (or select from a valid move set)

[vagabond11]

Thank you for helping dude, one last question. turn%2 What this mean?

[ne555]

http://en.wikipedia.org/wiki/Modulo_operator