Help! Debugging. Input glitched!

[ashwyn]

Hello,

Below is a program I wrote that is supposed to play the game Connect 4. I feel like its practically done, but I keep running into this weird bug randomly when playing it- and it causes me to not be able to finish a game.

After taking a few inputs, the program will suddenly drop, and it wont do anything other than let you input what you want in futility.

I feel like this might be an easy fix, and something that I'm just unaware of as a noobie.


The program seems to always have its hiccup on the test_gamestate function. So you may only need to look at line 126 and down.
EDIT: It seems this program is more busted than I am aware of- When I column is totally filled, I get a segmentation fault. And the game doesnt know when someone won. *sigh*

IMPORTANT NOTE ON RUNNING THIS PROGRAM:
It takes command line arguments to function properly.

please launch the program in the following format:
./a.out 2 [number of rows] [number of columns]
Ex:
./a.out 2 4 10

#include <iostream>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <string>

using namespace std;


//Validate Input
int getnumber(int cols){

   int n;
   cin >> n;
   while(cin.fail() || n < 0 || n >= cols)
   {
     cin.clear();
     cin.ignore();
     cout << "Please enter a valid column: ";
     cin >> n;
   }
   return n;
}





//Dropping the Token
void drop_token(char** board_ar, int rows, int cols, char player, int choice, int* position){
	bool placed = false;

	for(int i=0; i<rows;i++){
	   if(board_ar[i][choice] == 'Y' || board_ar[i][choice] == 'R'){  // Token gets placed ontop of another token
	      board_ar[i-1][choice] = player;
	      placed = true;
	      position[0] = i - 1;
	      position[1] = choice;
	      break;
	   }

	}
        if(placed == false){                                              // Token gets placed at the bottom of a column
	board_ar[rows - 1][choice] = player;    
	position[0] = rows - 1;
	position[1] = choice;
	}	

}



//Choosing a Column
int select_col(char** board_ar, int rows, int cols, char player){

   int choice = 0;   
   
 
   do{

   cout << "Player " << player << ", choose an appropriate column to drop your token in." << endl;
   choice = getnumber(cols);

   }while(board_ar[0][choice] == 'R' || board_ar[0][choice] == 'Y');
  
   return choice;	
  }




//Display Current Board
void display_board(char** board_ar,int rows,int cols){

   cout << "--------Columns--------" << endl;
   for(int i=0; i<cols;i++){
   cout << i;
   }
   cout << endl;
   for(int j=0;j<cols;j++){
      cout << "*";
   }
   cout << endl;
 
   for(int i=0; i<rows;i++){
      for(int j=0;j<cols;j++){
	 cout << board_ar[i][j];
      }
      cout << endl;
   } 
   cout << "\n\n\n" << endl;                // leave extra space on bottom
}


//Check Game State
int check_gamestate(char** board_ar, int rows, int cols, char player, int* position){

   //Checking the Gamestate: Seperate Counts for each:
   //1) Function that checks vertical match
   //2) Function that checks left and right match
   //3) Function that checks up left and down right
   //4) Function that cheks up right and down left


  int vert_token_count=0;
  if(position[0] + 3 < rows){
     cout << "Entered vert count" << endl;
     for(int j = 1;j<rows;j++){
       board_ar[position[0]+j][position[1]];
       if(board_ar[position[0]+j][position[1]] == player && position[0]+j < rows){
          cout << "Ping" << endl;
       }
     } 
  }
  //cout << "vertical token count = " << vert_token_count << endl;
  return 0;
}



//TEST FUNCTION:
//



int test_gamestate(char** board_ar, int rows, int cols, char player, int* position){

   int vertical = 1;
   int horizontal = 1;
   int diagonal1 = 1;//(\)
   int diagonal2 = 1;//(/)
   int i; //vert
   int ii; //horiz
   //Check vertical
   for(i = position[0] +1; board_ar[i][position[1]] == player && i < rows;i++,vertical++);  //down            *** May need to adjust rows
   for(i = position[0] -1; board_ar[i][position[1]] == player && i >= 0;i--,vertical++);   // up
   if(vertical >= 4)return 1;
   //Check Horizontal 
   for(ii = position[1] -1; board_ar[position[0]][ii] == player && ii >= 0;ii--, horizontal++) //left
   for(ii = position[1] +1; board_ar[position[0]][ii] == player && ii < cols;ii++, horizontal++) //right       *** May need to adjust cols
   if(horizontal >= 4)return 1;
   //Check Diagonal 1 (\)
   for(i = position[0] -1, ii = position[1] -1; board_ar[i][ii] == player && i >=0 && ii >=0; diagonal1++, i--, ii--); // up and left
   for(i = position[0] +1, ii = position[1] +1; board_ar[i][ii] == player && i < rows && ii < cols; diagonal1++,i++,ii++); // down and right
   if(diagonal1 >= 4)return 1;
   //Check Diagonal 2 (/)
   for(i = position[0] -1, ii = position[1] +1; board_ar[i][ii] == player && i >= 0 && ii < cols; diagonal2++, i--, ii++); // up and right
   for(i = position[0] +1, ii = position[1] -1; board_ar[i][ii] == player && i < rows && ii >= 0; diagonal2++, i++, ii--); // down and left
   if(diagonal2 >= 4)return 1;

   return 0;




}






/********************************
 COMMAND LINE ARGUMENTS MUST BE 
 ENTERED IN THE FOLLOWING ORDER:
 [NUMBER OF PLAYERS] [ROWS] [COLUMNS]
 *******************************/
int main(int argc, char* argv[]){
   int game_state = 0;                 // variable to check state of the game
   int choice = 0;                     // Selected column number
   int num_players = atoi(argv[1]);    // Number of players
   int rows = atoi(argv[2]);           // rows cmd line input
   int cols = atoi(argv[3]);           // columns cmd line input
   char player;                        // Current player
   int* position = new int[2];	       // Where token is placed (used to check game state)
   for(int i=0;i<2;i++)
      position[i] = 0;

   char** board_ar = new char*[rows];  // Connect 4 grid creation
   board_ar[0] = new char[rows*cols];
  
  for(int i =0;i<cols;i++){
      board_ar[i] = board_ar[0] + i*cols;                    //initialize board_ar with rows
   }

   for(int i=0; i<rows;i++){
      for(int j=0;j<cols;j++){
	 board_ar[i][j] = '0';                               // populate board_ar with initial chars
      }     
   }
   do{
   player = 'R';                                             // Player One Turn
   display_board(board_ar, rows, cols);

   choice = select_col(board_ar, rows, cols, player);
   
   drop_token(board_ar, rows, cols, player, choice, position);

   display_board(board_ar, rows, cols);

     //game_state = check_gamestate(board_ar, rows, cols, player, position);

   game_state = test_gamestate(board_ar, rows, cols, player, position);

      if(game_state == 0){
	 player = 'Y';

	 if(atoi(argv[1]) == 1){/*Ai_turn*/}
	 
	     
	 if(atoi(argv[1]) == 2){   // Player Two Turn
		   
	 display_board(board_ar, rows, cols);
 
      	 choice = select_col(board_ar, rows, cols, player);

	 drop_token(board_ar, rows, cols, player, choice, position);

      	 display_board(board_ar, rows, cols);

      	// game_state = check_gamestate(board_ar, rows, cols, player, position);
	 game_state = test_gamestate(board_ar, rows, cols, player, position);
	 }

      
      }
   }while(game_state == 0);
   if(game_state == 1){
   cout << "YOU WIN! WE DID IT!!!!" << endl;}
  // delete[][] board_ar;
return 0;
}

Thank you so much for looking at this.
I'm very grateful as it is due in just a few hours. ! :/

P.S. I know that I'm not using the 'check_gamestate' function.

[salem c]

1. Learn how to use a debugger.

 g++ -g main.cpp
$ gdb -q ./a.out
Reading symbols from ./a.out...done.
(gdb) run 2 4 10
Starting program: /home/sc/Documents/a.out 2 4 10
/// snipped
Player Y, choose an appropriate column to drop your token in.
4

0123456789
**********
0000000000
0000000000
00RYY00000
00RYR00000




5

5
^C
Program received signal SIGINT, Interrupt.
0x00000000004011bc in test_gamestate (board_ar=0x614c40, rows=4, cols=10, player=89 'Y', position=0x614c20) at main.cpp:139
139	   for(ii = position[1] -1; board_ar[position[0]][ii] == player && ii >= 0;ii--, horizontal++) //left
(gdb) bt
#0  0x00000000004011bc in test_gamestate (board_ar=0x614c40, rows=4, cols=10, player=89 'Y', position=0x614c20) at main.cpp:139
#1  0x0000000000401614 in main (argc=4, argv=0x7fffffffdf28) at main.cpp:222
(gdb) list
134	   //Check vertical
135	   for(i = position[0] +1; board_ar[i][position[1]] == player && i < rows;i++,vertical++);  //down            *** May need to adjust rows
136	   for(i = position[0] -1; board_ar[i][position[1]] == player && i >= 0;i--,vertical++);   // up
137	   if(vertical >= 4)return 1;
138	   //Check Horizontal
139	   for(ii = position[1] -1; board_ar[position[0]][ii] == player && ii >= 0;ii--, horizontal++) //left
140	   for(ii = position[1] +1; board_ar[position[0]][ii] == player && ii < cols;ii++, horizontal++) //right       *** May need to adjust cols
141	   if(horizontal >= 4)return 1;
142	   //Check Diagonal 1 (\)
143	   for(i = position[0] -1, ii = position[1] -1; board_ar[i][ii] == player && i >=0 && ii >=0; diagonal1++, i--, ii--); // up and left
(gdb) print horizontal 
$1 = -1829364223

So I pressed ctrl-c (that's the SIGINT) because the program had halted internally, and not processing any more input.
Notice the WTF value for horizontal.


2. Learn how to indent code properly.

int test_gamestate(char **board_ar, int rows, int cols, char player,
                   int *position)
{
  int vertical = 1;
  int horizontal = 1;
  int diagonal1 = 1;            //(\)
  int diagonal2 = 1;            //(/)
  int i;                        //vert
  int ii;                       //horiz
  //Check vertical
  for (i = position[0] + 1; board_ar[i][position[1]] == player && i < rows; i++, vertical++); //down            *** May need to adjust rows
  for (i = position[0] - 1; board_ar[i][position[1]] == player && i >= 0; i--, vertical++); // up
  if (vertical >= 4)
    return 1;
  //Check Horizontal
  for (ii = position[1] - 1; board_ar[position[0]][ii] == player && ii >= 0; ii--, horizontal++)  //left
    for (ii = position[1] + 1; board_ar[position[0]][ii] == player && ii < cols; ii++, horizontal++)  //right       *** May need to adjust cols
      if (horizontal >= 4)
        return 1;
  //Check Diagonal 1 (\)
  for (i = position[0] - 1, ii = position[1] - 1; board_ar[i][ii] == player && i >= 0 && ii >= 0; diagonal1++, i--, ii--);  // up and left
  for (i = position[0] + 1, ii = position[1] + 1; board_ar[i][ii] == player && i < rows && ii < cols; diagonal1++, i++, ii++);  // down and right
  if (diagonal1 >= 4)
    return 1;
  //Check Diagonal 2 (/)
  for (i = position[0] - 1, ii = position[1] + 1; board_ar[i][ii] == player && i >= 0 && ii < cols; diagonal2++, i--, ii++);  // up and right
  for (i = position[0] + 1, ii = position[1] - 1; board_ar[i][ii] == player && i < rows && ii >= 0; diagonal2++, i++, ii--);  // down and left
  if (diagonal2 >= 4)
    return 1;

  return 0;
}

Do you now see the oddness of your Horizontal checks compared to the others.
Just one missing ; and the character of the loops is completely changed.

FWIW, always write your empty statements like so, to make your intentions obvious.

for ( blah ) {
    ; // empty
}

[ashwyn]

Thank you for your guidance.

         ,     ,
           |\."./|
          / _   _ \
         / {|} {|} \  _
         \==  Y  ==/ ( \
          ;-._^_.-;   ) )
         /   \_/   \ / /
         |   (_)   |/ /
        /|  |   |  |\/
       | |  |   |  | |
        \|  |___|  |/
         '""'   '""'