Printing 'box' in array - c

Question

So I am facing hair loss day by day because of this sub-task required for my first year assignment.
I need to print a 'box' around the number at coordinate [5][5] / i.e center of the board during the initialization stage of the program.
The 'box' consists of "|" covering the sides and "_" on top and bottom of the number at coordinate [5][5].
When I execute this program, the board shows but the 'box' doesn't. Why is this happening??
Here is the code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
//FUNCTION: Draw the Board
int drawBoard()
{
//Declare array size
int board[9][9];
//initialize variables
int rows, columns, randomNumber, flag;
//random number seed generator
srand(time(NULL));
for ( rows = 0 ; rows < 9 ; rows++ )
{
for ( columns = 0 ; columns < 9 ; columns++ )
{
flag = 0;
do
{
//generate random numbers from 2 - 8
randomNumber = rand() %7 + 2;
board[rows][columns] = randomNumber;
//Display the 'box' if rows and columns == 5 / i.e - board[5][5]
if ( rows == 5 && columns == 5 )
{ //Checks for 2 adjacent numbers
if ( board[rows][columns] == board[rows - 1][columns] || board[rows][columns] == board[rows][columns - 1] )
{
flag = 0;
continue;
}
else
{
flag = 1;
//Print 'box'
marker( rows, columns );
}
}
//Checks for 2 adjacent numbers.
if ( board[rows][columns] == board[rows - 1][columns] || board[rows][columns] == board[rows][columns - 1] )
{
flag = 0;
continue;
}
else
//Prints the correct board
{
flag = 1;
printf( " %d ", board[rows][columns] );
}
} while ( flag == 0 ); //end outer do-while
}//end inner for-loop
printf("\n\n");
}//end outer for-loop
}//end FUNCTION drawBoard
//FUNCTION: Mark the surrounding of the number with "|" and "_" at board[5][5]
void marker( int x, int y, int** board )
{
board[x][y-1] == "\n _ ";
board[x][y+1] == "\n _ ";
board[x-1][y] == " |";
board[x+1][y] == "| ";
}
int main()
{
drawBoard();
}
TI

Answer 1

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
//FUNCTION: Draw the Board
char tochar(int i)
{
return i+'0';
}
void marker( int x, int y, char board[][19] );
int check(int x, int y, char board[][19])
{
if(x>1&&board[2*x+1][2*y+1]==board[2*x-1][2*y+1])
return 1;
if(y>1&&board[2*x+1][2*y+1]==board[2*x+1][2*y-1])
return 1;
return 0;
}
int drawBoard()
{
//Declare array size
char board[19][19];
memset(board,32, sizeof(board));
//initialize variables
int rows, columns, randomNumber, flag;
//random number seed generator
srand(time(NULL));
for ( rows = 0 ; rows < 9 ; rows++ )
{
for ( columns = 0 ; columns < 9 ; columns++ )
{
flag = 0;
do
{
//generate random numbers from 2 - 8
randomNumber = rand() %7 + 2;
board[2*rows+1][2*columns+1] = tochar(randomNumber);
//Display the 'box' if rows and columns == 5 / i.e - board[5][5]
if ( rows == 4 && columns == 4 )
{ //Checks for 2 adjacent numbers
if ( check(rows, columns, board))
{
flag = 0;
}
else
{
flag = 1;
marker( 2*rows+1, 2*columns+1, board );
//Print 'box'
}
}
else
{
//Checks for 2 adjacent numbers.
if ( check(rows, columns, board))
{
flag = 0;
}
else
//Prints the correct board
{
flag = 1;
// printf( " %c ", board[2*rows+1][2*columns+1] );
}
}
} while ( flag == 0 ); //end outer do-while
}//end inner for-loop
printf("\n\n");
}//end outer for-loop
for(rows=0;rows<19;rows++)
{
for(columns=0;columns<19;columns++)
{
printf("%c",board[rows][columns]);
}
printf("\n");
}
}//end FUNCTION drawBoard
//FUNCTION: Mark the surrounding of the number with "|" and "_" at board[5][5]
void marker( int x, int y, char board[][19] )
{
board[x][y-1] = '|';
board[x][y+1] = '|';
board[x-1][y] = '_';
board[x+1][y] = '_';
/*
192
191
217
218
*/
}
int main()
{
drawBoard();
}

Answer 2

void marker( int x, int y, int** board )
{
board[x][y-1] == "\n _ ";
board[x][y+1] == "\n _ ";
board[x-1][y] == " |";
board[x+1][y] == "| ";
}
This won't work. The '==' is for comparing, not assigning. You need a '='.
However, board is an array of int, you can't assign a const char* (because that's what "something" is) in an array of int. Your board should be an array of char, and then you can assign like this:
void marker( int x, int y, char** board )
{
board[x][y-1] = '_';
board[x][y+1] = '_';
board[x-1][y] = '|';
board[x+1][y] = '|';
}
Another problem is that the center of the board is at index [4][4], the fifth element of a table of size 9. But that is a smaller problem...

Answer 3

I see what you want to do here, this isn't the way I usually think, so I may be not helpfull :s
first, a mistake:
in "drawboard": marker( rows, columns )
prototype of "marker": void marker( int x, int y, int** board ). I don't think compilation with flag will work (and yes, flags ARE helpfull, try "gcc -Wall -Wextra -Werror")
Moreover, I think you should re-think your function "marker", it can't work.
I think board[x][y-1] = "\n _ " would do the trick, if you return(board[x][y-1]) but again, I would have work with a char**, not an integer tab, and with many short functions (and used write instead of printf :p)