/**
* fifteen.c
*
* Computer Science 50
* Problem Set 3
*
* Implements Game of Fifteen (generalized to d x d).
*
* Usage: fifteen d
*
* whereby the board's dimensions are to be d x d,
* where d must be in [DIM_MIN,DIM_MAX]
*
* Note that usleep is obsolete, but it offers more granularity than
* sleep and is simpler to use than nanosleep; `man usleep` for more.
*/
#define _XOPEN_SOURCE 500
#include <cs50.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
// constants
#define DIM_MIN 3
#define DIM_MAX 9
// board
int board[DIM_MAX][DIM_MAX];
int b;
// dimensions
int d;
// prototypes
void clear(void);
void greet(void);
void init(void);
void draw(void);
bool move(int tile);
bool won(void);
int main(int argc, string argv[])
{
// ensure proper usage
if (argc != 2)
{
printf("Usage: fifteen d\n");
return 1;
}
// ensure valid dimensions
d = atoi(argv[1]);
if (d < DIM_MIN || d > DIM_MAX)
{
printf("Board must be between %i x %i and %i x %i, inclusive.\n",
DIM_MIN, DIM_MIN, DIM_MAX, DIM_MAX);
return 2;
}
// open log
FILE* file = fopen("log.txt", "w");
if (file == NULL)
{
return 3;
}
// greet user with instructions
greet();
// initialize the board
init();
// accept moves until game is won
while (true)
{
// clear the screen
clear();
// draw the current state of the board
draw();
// log the current state of the board (for testing)
for (int i = 0; i < d; i++)
{
for (int j = 0; j < d; j++)
{
fprintf(file, "%i", board[i][j]);
if (j < d - 1)
{
fprintf(file, "|");
}
}
fprintf(file, "\n");
}
fflush(file);
// check for win
if (won())
{
printf("ftw!\n");
break;
}
// prompt for move
printf("Tile to move: ");
int tile = GetInt();
// quit if user inputs 0 (for testing)
if (tile == 0)
{
break;
}
// log move (for testing)
fprintf(file, "%i\n", tile);
fflush(file);
// move if possible, else report illegality
if (!move(tile))
{
printf("\nIllegal move.\n");
usleep(500000);
}
// sleep thread for animation's sake
usleep(500000);
}
// close log
fclose(file);
// success
return 0;
}
/**
* Clears screen using ANSI escape sequences.
*/
void clear(void)
{
printf("\033[2J");
printf("\033[%d;%dH", 0, 0);
}
/**
* Greets player.
*/
void greet(void)
{
clear();
printf("WELCOME TO GAME OF FIFTEEN\n");
usleep(2000000);
}
/**
* Initializes the game's board with tiles numbered 1 through d*d - 1
* (i.e., fills 2D array with values but does not actually print them).
*/
void init(void)
{
for(int i = 0, j = 0, k = ((d*d)-1); i < d; j++, k--)
{
if(j == d)
{
i = i + 1;
j = 0;
}
board[i][j] = k;
}
if((d*d)%2 == 0)
{
board[(d-1)][(d-2)] = 2;
board[(d-1)][(d-3)] = 1;
}
board[(d-1)][(d-1)] = 0;
b = board[(d-1)][(d-1)];
}
/**
* Prints the board in its current state.
*/
void draw(void)
{
for(int i = 0, j = 0; i !=(d-1) || j!=d; j++)
{
if(j == d)
{
i = i + 1;
j = 0;
printf("\n");
}
if(board[i][j] == 0) //b used to be 99
{
printf(" _");
}
else
{
printf(" %2d", board[i][j]);
}
}
printf("\n");
}
/**
* If tile borders empty space, moves tile and returns true, else
* returns false.
*/
bool move(int tile)
{
//find tile
for(int i = 0, j = 0; i !=(d-1) || j!=d; j++)
{
if(j == d)
{
i = i + 1;
j = 0;
}
if (board[i][j] == tile)
{
//check if tile position is in valid perimeter of blank space
if (board[i+1][j] == b)
{
board[i+1][j] = tile;
board[i][j] = 0;
b = board[i][j];
return true;
}
if (board[i-1][j] == b)
{
board[i-1][j] = tile;
board[i][j] = 0;
b = board[i][j];
return true;
}
if (board[i][j+1] == b)
{
board[i][j+1] = tile;
board[i][j] = 0;
b = board[i][j];
return true;
}
if (board[i][j-1] == b)
{
printf("%i", board[i][j-1]);
board[i][j-1] = tile;
board[i][j] = 0;
b = board[i][j];
return true;
}
}
}
return false;
}
/**
* Returns true if game is won (i.e., board is in winning configuration),
* else false.
*/
bool won(void)
{
for(int i = 0, j = 0, k = 1; i !=(d-1) || j!=d; j++)
{
if(j == d)
{
i = i + 1;
j = 0;
}
if (k == (d*d)-1)
{
return true;
}
if (board[i][j] == k)
{
k = k + 1;
}
}
return false;
}
I originally had
board[(d-1)][(d-1)] = 0;
equal to 99 along with the move function look for 99. For my problem set I was supposed to use 0. Once I changed 99 to 0, for some reason 0 is being found if board[i][j-1] even if that means board[2][-1]. Why is that allow/why does that equal 0? and how can I disable this?
