Tic Tac Toe Minimax problem

[J031]

Hello please help me with this tic tac toe program.I am trying to implement Minimax in tic tac toe and it is not working.Please correct my code.Also i need
to do this in turbo c++.

#include<iostream.h>
#include<math.h>
#include<string.h>
#include<graphics.h>
#include<bios.h>
#include<dos.h>
#include<stdlib.h>
#include<conio.h>
char board[3][3];
int key=0,g=0;
void startboard()
{
  for(int i=0;i<3;++i)
    {
      for(int j=0;j<3;++j)
	board[i][j]=' ';
    }
}
void draw_board()
{
  rectangle(getmaxx()/2-62,getmaxy()/2-65,getmaxx()/2+60,getmaxy()/2+80);
  //vert
  line(getmaxx()/2-22,getmaxy()/2-64,getmaxx()/2-22,getmaxy()/2+80);
  line(getmaxx()/2+18,getmaxy()/2-64,getmaxx()/2+18,getmaxy()/2+80);
  //horiz
  line(getmaxx()/2-60,getmaxy()/2-14,getmaxx()/2+60,getmaxy()/2-14);
  line(getmaxx()/2-60,getmaxy()/2+30,getmaxx()/2+60,getmaxy()/2+30);


 int m=0,n=0;
  for(int i=35;i<=45;i+=5)
  {
    for(int j=13;j<=19;j+=3)
      {
	gotoxy(i,j);
	cout<<board[n][m];
	++n;
      }
    n=0;
    ++m;
   }
}
void user()
{
  int row,col;
  gotoxy(1,1);
  cout<<"\n\nEnter input row & column:\n";
  cin>>row>>col;
  board[row][col]='X';
}
int check(char ch)
{
  int e=0;
  for(int x=0;x<3;++x)
    for(int y=0;y<3;++y)
       if(board[x][y]!=' ')
	 ++e;
  if(e>=8)
    return 1;
  for (int i=0; i<3;i++)
	 if (board [i][0] == board [i] [1] && board [i][0] ==      board [i] [2] && board [i] [0] == ch)return 0;

for (i=0; i<3;i++)
	if (board [0][i] == board [1] [i] && board [0][i] == board [2] [i] && board [0] [i] == ch) return 0;


 if (board [0][0] == board [1] [1] && board [1][1] == board [2] [2] && board [1] [1] == ch)return 0;
 if (board [0][2] == board [1] [1] && board [1][1] == board [2] [0] && board [1] [1] == ch)return 0;
}
void func()
{
  for(int i=0;i<3;++i)
    for(int j=0;j<3;++j)
      {
	if(board[i][j]==' ')
	{
	  board[i][j]='O';goto d;
	}
      }
  d:
}
struct score
{
  int x,y,sco;
}z[7];
int best=0,value=0;
int computer(int player,int &x,int &y)\\problem
{
   if(player==1)
     best=-1000;
   if(player==-1)
     best=1000;
  if(check('X')==0) return -10;
  if(check('O')==0) return 10;
  if(check('X')==1&&check('O')==1) return 0;
  for(int i=0;i<3;++i)
    {
      for(int j=0;j<3;++j)
	{
	  if(board[i][j]==' ')
	    {
	       board[i][j]='O';
	       value=computer(-player,i,j);
	       board[i][j]=' ';
	    }
	  if(player==-1&&value<best)
	    best=value;
	  else if(player==1&&value>best)
	  {
	    best=value;
	    x=i;y=j;
	  }
       }
    }
  return best;
}
void main()
{
  randomize();
  int gd=DETECT,gm,player;
  initgraph(&gd,&gm,"");
//  anim();
  int a,b;
  startboard();
  for(int i=0;i<5;++i)
    {
      draw_board();
      user();
      a=b=0;
      computer(1,a,b);
      board[a][b]='O';
      if(check('X')==0)
	{
	  cout<<"\n\n\nX won";break;
	}
      if(check('O')==0)
	{
	  cout<<"\n\n\nO won";break;
	}

      closegraph();
      initgraph(&gd,&gm,"");

    }
  getch();
}

[TarikNeaj]

Edit your post and use code tags for your code - http://www.cplusplus.com/articles/jEywvCM9/

[J031]

done

[J031]

Please someone help.I am hoping to include this in my project in which submission date is Wednesday.I have googled for weeks still i can't implement this.

[Thomas1965]

What is actually the problem ?

[doug4]

I don't know much about game theory, so I can't help you with your algorithm. However, your check() function doesn't return a value if all of the "if" statements fail.

[48T7M4Gy]

Hi there JO31
1. First step is for you to understand and describe to us what the minimax algorithm is. Just a few short sentences will do.
2. Then you write up a plan - pseudocode is not a bad way of doing that.
3. Then you present it here with another post - you can even highlight the troublespot areas in that.
4. You can also pinpoint the corresponding areas in your code above if you like so we can get straight onto the problem for you instead of wading through piles of superfluous ...

Best wishes
Cheers :)

[J031]

Ok kemort i will try to do that

[48T7M4Gy]

Good man/woman. Winners are grinners!
Cheers

[J031]

I think i implemented it.But it is not blocking all my moves.

[48T7M4Gy]

So where in the problem? Where is the blocking code, and don't forget each side only has one move so at any particular turn, not necessarily every opponents move can be blocked of course.