Problem

source.obj : error LNK2001: unresolved external symbol "bool __cdecl safe(int)" (?safe@@YA_NH@Z)


Would anyone know why I get this message when ever i try to run my program.

Code:

#include <iostream>

using namespace std;



int num_of_suc;
int nth_next_move(int n, int GameState[9]);
void nth_next_game(int n, int GameState[9], int NextGame[9]);
int number_of_moves(int GameState[9]);
void not_in_state(int GameState[], int Return[]);
bool member(int e, int GameState[9]);
bool safe(int);
bool game=false;
void drawboard();
char board[9]={0,1,2,3,4,5,6,7,8};
void moves(int);
void turn(int, int);







	void nth_next_game(int n, int GameState[9], int NextGame[9])
	{
		for(int i=0;i<9;i++)
		{
			if(i<number_of_moves(GameState))
				NextGame[i]=GameState[i];
			else if (i == number_of_moves(GameState))
				NextGame[i]=nth_next_move(n,GameState);
			else
				NextGame[i]=-1;
		}
		
	}



	int number_of_moves(int GameState[9])
	{
		int i=0;
		while(GameState[i] != -1)
			i++;

		return i;
	}

	int nth_next_move(int n, int GameState[9])
	{
		int NotIn[9];
		not_in_state(GameState,NotIn);
		return NotIn[n-1];
	} 




	void not_in_state(int GameState[], int ret[])
	{
		int Counter=0;

		for(int i=1;i<=9;i++)
		if(!member(i,GameState))
		{
			ret[Counter]=i;
			Counter++;
		}

		for(i=Counter;i<9;i++)
			ret[i] = -1;

	}


	bool member(int e, int GameState[9])
	{
		bool flag=false;

		for(int i=0;i<9;i++)
			if(GameState[i]==e)
				flag =true;

		return flag;
	}

	bool safe (int gamestate[9])
	{
		//o's move only!!!!!!

		bool safeflag=false;
		num_of_suc=9-number_of_moves(gamestate);

		int nextgame[9];

		if (number_of_moves(gamestate)%2==1)
		{
			for (int i=1; i<=num_of_suc; i++)
			{
				nth_next_game(i, gamestate, nextgame);
				if (safe(nextgame))
					safeflag=true;
			}
		}
		else // x's move only!!!!!!
		{
			bool safeflag=true;

			if (number_of_moves(gamestate)%2==1)
			{
				for (int i=1; i<=num_of_suc; i++)
				{
					nth_next_game(i, gamestate, nextgame);
					if (!safe(nextgame))
						safeflag=false;
				}
			}
		}
		return 0;
	}

	void moves(int m)
	{
		cin >> m;

		switch(m)
		{
			case 1:	if ((m==1)&&(board[0]!='x')&&(board[0]!='o'))
						board[0]='x';
					break;
			case 2:	if ((m==2)&&(board[1]!='x')&&(board[1]!='o'))
						board[1]='x';
					break;
			case 3:	if ((m==3)&&(board[2]!='x')&&(board[2]!='o'))
						board[2]='x';
					break;
			case 4:	if ((m==4)&&(board[3]!='x')&&(board[3]!='o'))
						board[3]='x';
					break;
			case 5:	if ((m==5)&&(board[4]!='x')&&(board[4]!='o'))
						board[4]='x';
					break;
			case 6:	if ((m==6)&&(board[5]!='x')&&(board[5]!='o'))
						board[5]='x';
					break;
			case 7:	if ((m==7)&&(board[6]!='x')&&(board[6]!='o'))
						board[6]='x';
					break;
			case 8:	if ((m==8)&&(board[7]!='x')&&(board[7]!='o'))
						board[7]='x';
					break;
			case 9:	if ((m==9)&&(board[8]!='x')&&(board[8]!='o'))
						board[8]='x';
			default: cout << "Cannot move there!" << endl;
		}

	}


	////////////////////////////////////////////////////
	//////////  Main Funciton  /////////////////////////
	////////////////////////////////////////////////////

	void main()
	{
		board[0]=' ';
		board[1]=' ';
		board[2]=' ';
		board[3]=' ';
		board[4]=' ';
		board[5]=' ';
		board[6]=' ';
		board[7]=' ';
		board[8]=' ';

		int Game[9]={3,5,7,8,1,-1,-1,-1,-1};
		int Next[9];

		char x;

		cout << "Would you like to play a game of Tic Tac Toe (Y/N)?" << endl;

		cin >> x;

		if (x=='y')
			game=false;
		else
			if (x=='n')
				game=true;

		while (!game)
		{
			for (int count=0; count<9; count++)
			{
			
				cout << "Choose a number between 1 and 9 to move" << endl;
				drawboard();

				if ((count==0)||(count==2)||(count==4)||(count==6)||(count==8))
				{
					moves(Game[count]);
				}else
				{
					if (safe(Game[count]))
					{
						cout << "Game is Safe!" << endl;
					}
				}

			}

			if (count==9)
			{
				game=true;
			}
		}

	}

	void drawboard()
	{
		cout << board[0] << "|" << board[1] << "|" << board[2] << endl;
		cout << board[3] << "|" << board[4] << "|" << board[5] << endl;
		cout << board[6] << "|" << board[7] << "|" << board[8] << endl;
	}

There is my code..................I believe that the error is comeing form my use of the safe function (safe(Game[count]));

Look at the declaration of safe.
Then look at the definition of safe.

See any differences?

By the way.
I don't know why people keep asking about the same problem.
unresolved external symbol"...."
And it's always the same answer.

My question is:
Is there any other cause for this error?

Well all i can tell you is that look at your functions because i see that you are colling some functions but as i know in C++ when you build a function you build it at at the header files and then the main pary you do at .cpp hope this helps
for example this bool member(int e, int GameState[9]);
you save as member.h and then the main part you do it in member.cpp this will get rid of it the LINK ERROR OK and you will have to do all for the functions that you colled

Umm safe is declared with an int argument. Then later on I use add safe(int gamestate[9]) that is what you are supposed to do. Now if I am not supposed to use the line if (safe(Game[9])) like that then how am I supposed to use it?

You have to figure out how your function should look like. Then, write the function. Your forward declaration must look exactly the same as your implementation. It's basically the first line copied and with a semicolon. Compare your declaration with your implementation, they don't match.

Well i guess im not seeing the differance between

Code:

bool safe(int);

      bool safe(int gamestate[9])
      {
      }

safe(Next[9]);

All three statements have one argument that is of type int. So whats the deal?

Ok i changed my implimentation of safe(blah blah) to bool safe (blah blah). Is that what yall where talking about?