fifteen.c

/**
 * 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 * Note that usleep is obsolete, but it offers more granularity than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

// init Global values
int x, y, i, j;
// board
int board[DIM_MAX][DIM_MAX];

// 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(1000000);
}

/**
 * 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)
{
    //initialise int c for board backward
    int c=0;
    int all_board = (d*d);
    //loop row
    for (int i=0; i<d; i++)
    {
        //loop col
        for (int j=0; j<d; j++)
        {
            //fill the board with values
            c++;
            board[i][j]= all_board - c;
            
        }
    }
   
    
    //if odd board
    if ((d %2) ==0)
    {
       
        board[d - 1][d - 2] = 2;
        board[d - 1][d - 3] = 1; 
    }
}



/**
 * Prints the board in its current state.
 */
void draw(void)
{
  //  int n=0;
 // loop through the board
    for (int i = 0; i<d; i++)
    {
        for (int j = 0; j<d; j++)
        {
            //n++;
            
             if (board[i][j] == 0) 
            {
            // draw board cell
              printf("  _");
            }
          else {
              printf("%2d ", board[i][j]);
          }
 
        }
               //make new row
        printf("\n");
    }
}

/**
 * If tile borders empty space, moves tile and returns true, else
 * returns false. 
 */
bool move(int tile)
{
   
     //loop through the row
     for (int x=0; x<d; x++)
     {
         // loop through the col 
         for (int y=0; y<d; y++)
         {
             // if cell is on the board
             if (board[x][y]==tile)
             {
                //i = x;
                //j = y;
                //check left border
                 if(board[x-1][y]==0)
                 {
                     //move tile left
                     board[x-1][y]=tile;
                     //reassigh tile to blank
                     board[x][y]=0;
                     return true;
                 }
                 //if above is blank
                 else if (board[x][y-1]==0)
                 {
                     //move tile up and reassign blank
                     board[x][y-1]=tile;
                     board[x][y]=0;
                     return true;
                 }
                 //if right cell is blank
                 else if (board[x][y+1]==0)
                 {
                     //move tile right and reassign blank
                     board[x][y+1]=tile;
                     board[x][y]=0;
                     return true;
                 }
                 //if bottom cell is blank
                 else if (board[x+1][y]==0)
                 {
                     //move tile down and reassign blank
                     board[x+1][y]=tile;
                     board[x][y]=0;
                     return true;
                 }                                              
                 //otherwise do nothing:)
                 return false;
             }
         }
     }
     return 0;
}


/* * Returns true if game is won (i.e., board is in winning configuration), 
 * else false.
 */
bool won(void)
{
    int win=0;
    for (i=0; i<d; i++)
    {
        for (j=0; j<d; j++)
        {
            if (board[i][j]!=win)
            {
            return false;
            win=win+1;
            }
        }
    }
    return true;
}