populating arrays

I am new to C.

I am trying to make sure that the rows and column adjacent to the row and column the user input are blocked( being populated by an 'X' behind the UI so a move can not be made there. This is to stay out of the line of the queens moves. Is my for loop correct? how can I display the 'X' to make sure that these spaces are being populated?
Thanks,

Code:

#include <stdio.h>
#include <ctype.h>
#define SIZE 8 /* Size of board*/

/* function prototype */
void display(char board[] [SIZE]);
int valid_moves(char board[] [SIZE], int moves[] [SIZE], char player);

int main()
{
      char board [SIZE] [SIZE] ={ 0 }; /* The board*/
      int moves[SIZE] [SIZE] ={0}; /* valid moves */
      int row = 0;
      int col = 0;
      char queenie = 'Q';     /* user selection*/
      int y =0;        /* column number*/
      int x =0;         /* row number*/
      char player = 'Q';

       /* empty all the squares */
      for(row = 0; row < SIZE; row++)
        for(col = 0; col < SIZE; col++)
          board[row] [col] = ' ';



      
      /*fflush(stdin);          /*flush the buffer: keyboard--stdin*/
      printf("please enter the row numer 0-7 and column number 0-7 to place the queen:");
      scanf("%d %d", &x,&y);

       board[x][y]='Q';
		
	   for(x=x; x-1==0 && x+1==7; x++)
		{
			x='X';
		printf("board mark",board[x][y]);		
		}
		for(x= x; x-1==0 && x+1==7; x--)
		{
			x='X';
					
		}
		for(y= y; y-1==0&&y+1==7; y++)
		{
		y='X';
					
		}
		for(y= y; y-1==0&&y+1==7; y--)
		{
		y='X';
				
		}
				
	

      
      if(x<0 && y<0 || x>SIZE && y>SIZE)
      {
            printf(" That is an invalid entry!\n");
      }
     

	display(board);

}

/* display board funtion definition*/
void display(char board[] [SIZE])
{
      int row = 0;      /* row index */
      int col = 0;      /* col index */
      char col_label = 'a';         /* column label */

      printf("\n ");    /*start top line */
      for(col = 0; col<SIZE; col++)
      printf("   %c", col_label+col);    /* display the top line*/
      printf("\n");     /*end of top line*/

/*display  the intermediate rows*/
      for(row = 0; row < SIZE; row++)
      {
      printf("   +");
      for(col = 0; col<SIZE; col++)
      printf("---+");
      printf("\n%2d|",row + 1);

      for(col = 0; col< SIZE; col++)
      printf(" %c |", board[row][col]);   /* display counters in row*/
      printf("\n");
      }

      printf("   +");   /*start the bottom line*/
      for(col = 0; col<SIZE ; col++)
      printf("---+");   /*display the bottom line*/
      printf("\n");     /* end bottom line*/
      }

This is a strange piece of code. In the loop you are using x as an index. In the start of the loop you are always setting x to 'X'. So the x++ in the loop makes no sense. So you are always printing the same board [x][y].

Code:

for(x=x; x-1==0 && x+1==7; x++)
{
  x='X';
  printf("board mark",board[x][y]);
}

The same with the others. Usually one would introduce a new variable to use as variable in the loop.

Also, x is an integer, you can not assign it a char value. atleast you can, from what i believe, it will assign the ascii value. You need to either make a second variable thats char data type, or like shiro says, create a second variable of type int to increment the for loop. You will then have to change the data type of x to char.

p.s. ascii value of 'X' is 88.

Sorry is this better.

Code:

#include <stdio.h>
#include <ctype.h>
#define SIZE 8 /* Size of board*/

/* function prototype */
void display(char board[] [SIZE]);
int valid_moves(char board[] [SIZE], int moves[] [SIZE], char player);

int main()
{
      char board [SIZE] [SIZE] ={ 0 }; /* The board*/
      int moves[SIZE] [SIZE] ={0}; /* valid moves */
      int row = 0;
      int col = 0;
      char queenie = 'Q';     /* user selection*/
      int y =0;        /* column number*/
      int x =0;         /* row number*/
      char player = 'Q';
	  int i =0;

       /* empty all the squares */
      for(row = 0; row < SIZE; row++)
        for(col = 0; col < SIZE; col++)
          board[row] [col] = ' ';



      
      /*fflush(stdin);          /*flush the buffer: keyboard--stdin*/
      printf("please enter the row numer 0-7 and column number 0-7 to place the queen:");
      scanf("%d %d", &x,&y);

       board[x][y]='Q';


	   for(i=x; i-1==0 && i+1==7; i++)
		{
			i='X';
			
		}
		for(i= x; i-1==0 && i+1==7; i--)
		{
			i='X';
					
		}
		for(i= y; i-1==0&&i+1==7; i++)
		{
		i='X';
					
		}
		for(i= y; i-1==0&&i+1==7; i--)
		{
		i='X';
				
		}
				
	

      
      if(x<0 && y<0 || x>SIZE && y>SIZE)
      {
            printf(" That is an invalid entry!\n");
      }
     

	display(board);

}

/* display board funtion definition*/
void display(char board[] [SIZE])
{
      int row = 0;      /* row index */
      int col = 0;      /* col index */
      char col_label = 'a';         /* column label */

      printf("\n ");    /*start top line */
      for(col = 0; col<SIZE; col++)
      printf("   %c", col_label+col);    /* display the top line*/
      printf("\n");     /*end of top line*/

/*display  the intermediate rows*/
      for(row = 0; row < SIZE; row++)
      {
      printf("   +");
      for(col = 0; col<SIZE; col++)
      printf("---+");
      printf("\n%2d|",row + 1);

      for(col = 0; col< SIZE; col++)
      printf(" %c |", board[row][col]);   /* display counters in row*/
      printf("\n");
      }

      printf("   +");   /*start the bottom line*/
      for(col = 0; col<SIZE ; col++)
      printf("---+");   /*display the bottom line*/
      printf("\n");     /* end bottom line*/
      }

Wrong again, now in the for loop, you are assigning i = 'X' it wont work. i is type integer. You need to keep your for loop using x and make i type char. And keep your i = 'X'.

Better?

Code:

#include <stdio.h>
#include <ctype.h>
#define SIZE 8 /* Size of board*/

/* function prototype */
void display(char board[] [SIZE]);
int valid_moves(char board[] [SIZE], int moves[] [SIZE], char player);

int main()
{
      char board [SIZE] [SIZE] ={ 0 }; /* The board*/
      int moves[SIZE] [SIZE] ={0}; /* valid moves */
      int row = 0;
      int col = 0;
      char queenie = 'Q';     /* user selection*/
      int y =0;        /* column number*/
      int x =0;         /* row number*/
      char player = 'Q';
	  char i ='X';

       /* empty all the squares */
      for(row = 0; row < SIZE; row++)
        for(col = 0; col < SIZE; col++)
          board[row] [col] = ' ';



      
      /*fflush(stdin);          /*flush the buffer: keyboard--stdin*/
      printf("please enter the row numer 0-7 and column number 0-7 to place the queen:");
      scanf("%d %d", &x,&y);

       board[x][y]='Q';
						
	   for(x=x; x-1==0 && x+1==7; x++)
		{
			i='X';
			
		}
		for(x= x; x-1==0 && x+1==7; x--)
		{
			i='X';
					
		}
		for(x= y; x-1==0&&x+1==7; x++)
		{
		i='X';
					
		}
		for(x= y; x-1==0&&x+1==7; x--)
		{
		i='X';
				
		}
				
	

      
      if(x<0 && y<0 || x>SIZE && y>SIZE)
      {
            printf(" That is an invalid entry!\n");
      }
     

	display(board);

}

/* display board funtion definition*/
void display(char board[] [SIZE])
{
      int row = 0;      /* row index */
      int col = 0;      /* col index */
      char col_label = 'a';         /* column label */

      printf("\n ");    /*start top line */
      for(col = 0; col<SIZE; col++)
      printf("   %c", col_label+col);    /* display the top line*/
      printf("\n");     /*end of top line*/

/*display  the intermediate rows*/
      for(row = 0; row < SIZE; row++)
      {
      printf("   +");
      for(col = 0; col<SIZE; col++)
      printf("---+");
      printf("\n%2d|",row + 1);

      for(col = 0; col< SIZE; col++)
      printf(" %c |", board[row][col]);   /* display counters in row*/
      printf("\n");
      }

      printf("   +");   /*start the bottom line*/
      for(col = 0; col<SIZE ; col++)
      printf("---+");   /*display the bottom line*/
      printf("\n");     /* end bottom line*/
      }

Yes, better, but there are still flaws. why in your for loop is there x = x. Whats the point? Also, why are you using multiple for loops that all make i = 'X' which was done by the inizialization?

Check your personal messages, I have sent you something

ok, so what's the problem now? it compiles and works as well, but one thing, arrays in C are from 0 to N-1, so the first col in your program is 0