CS50 problem set3

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 * Note that usleep is obsolete, but it offers more granularity than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

// 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(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)
{
    int k=d*d-1;
    for(int i =0;i<d;i++)
        {
            for(int j=0;j<d;j++)
                {
                    
                    board[i][j] = k--;
                    //swapping values for 2 and 1
                     if((d*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)
{
    for(int i=0;i<d;i++)
        {
            for(int j=0;j<d;j++)
                {
                    if(board[i][j]>=10)
                        {
                          printf(" %d",board[i][j]);
                        }
                    if(board[i][j] <10 && board[i][j] >=1)
                        {
                            printf(" %2d",board[i][j]);
                        }
                    if(board[i][j] == 0)
                        {
                            printf(" -");
                        }
                }
        printf("\n");        
        }
}

/**
 * If tile borders empty space, moves tile and returns true, else
 * returns false. 
 */
bool move(int tile)
{
    for(int i=0;i<=d;i++)
        {
            for(int j=0;j<d;j++)
                {
                    //Locating tile in the box
                    if(board[i][j]==tile)
                        {
                         //Checking if deck below is empty and within the bounds of d
                          if(board[i+1][j]==0 && (i+1 <d))
                            {
                              board[i+1][j]=tile;
                              board[i][j]=0;
                              return true;
                            }
                         //Checking if deck above is empty and within the bounds of d
                          if(board[i-1][j]==0 && (i-1 >=0))
                             {
                              board[i-1][j]=tile;
                              board[i][j]=0;
                              return true;
                             } 
                          //Checking if deck to the right is empty and within the bounds of d
                          if(board[i][j+1]==0 && (j+1 <d))
                            {
                              board[i][j+1]=tile;
                              board[i][j]=0;
                              return true;
                            }
                          //Checking if below deck to the left and within the bounds of d
                          if(board[i][j-1]==0 && (j-1 >=0))
                             {
                              board[i][j-1]=tile;
                              board[i][j]=0;
                              return true;
                             }
                          else
                                {
                                    return false;
                                }
                        }
                }        
        }
     return false;     
} 
      
/**
 * Returns true if game is won (i.e., board is in winning configuration), 
 * else false.
 */
bool won(void)
{
    int correct[DIM_MAX][DIM_MIN];
    int k=d*d-1;
    for(int i =0;i<d;i++)
        {
         for(int j=0;j<d;j++)
                { 
                    
                    correct[i][j]=k--;
                    if(correct[i][j]==0)
                        {
                            correct[i][j] =0;
                        }
                }
        }
    for(int i=0;i<d;i++)
        {
            for(int j=0;j<d;j++)
                {
                    if(correct[i][j]!=board[i][j])
                        {
                            return 0;
                        }
                    else
                        {
                            return 1;
                        }
                }
        }
    return false;
}