CS50_pset3_fifteen

/**
 * fifteen.c
 *
 * 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 * Note that usleep is obsolete, but it offers more granularity than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++)
            {
                if(board[i][j] == 0 )
                {
                    fprintf(file, " _");

                }else if(board[i][j] != 0)
                {
                    fprintf(file, "%2i", 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 = get_int();

        // 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 init_value = (d*d)-1;

        for (int i = 0; i < d; i++) // d is dimention, this for loop affect row
            {
                for (int j = 0; j < d; j++) // d is dimention, this for loop affect coloumn
                {
                    board[i][j] = init_value;
                    init_value--;
                }
            }

        if (d%2==0){ // if modulo 2 gives a 0, means it's even, time to swap
            //swapping [3][1] and [3][2] if even
            int x = board[d-1][d-3];
            int y = board[d-1][d-2];
            board[d-1][d-3] = y;
            board[d-1][d-2] = x;
        }

}


/**
 * 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] == 0)
            {
                printf(" _");

            }else if(board[i][j] != 0)
            {
                printf("%2i", board[i][j]);

            }

            if (j < d - 1)
            {
                printf("|");
            }


        }
        printf("\n");
    }

}

/**
 * If tile borders empty space, moves tile and returns true, else
 * returns false.
 */
bool move(int tile)
{
    // user will key in a number
    //use this int to match with the board location
    //once found
    //program the number keyed in to swap position
    //BUT ONLY CAN SWAP IF ITS LEGAL Eg, up down left right

    int loc_x;
    int loc_y;

    if(tile > (d*d)-1 || tile < 1){
        return false;
    }


    for (int x=0; x < d; x++){
        for (int y=0; y < d; y++){

            if (board[x][y] == tile){ // finds the tile to move location
                // tile_select = board[x][y]; aka tile.
                // now, need to check if legal to swap.
                loc_x = x;
                loc_y = y;
            }
        }
    }

    if (board[loc_x+1][loc_y] == 0 && (loc_x+1 < d)){      // check below
        board[loc_x+1][loc_y] = board[loc_x][loc_y];        // value above 0 is replaced with non-0
        board[loc_x][loc_y] = 0;    // value above 0 is now 0
        return true;
    }else if (board[loc_x-1][loc_y] == 0 && (loc_x-1 >= 0)){      // check above
        board[loc_x-1][loc_y] = board[loc_x][loc_y];        // value above 0 is replaced with non-0
        board[loc_x][loc_y] = 0;    // value above 0 is now 0
        return true;
    }else if (board[loc_x][loc_y+1] == 0 && (loc_y+1 < d)){      //check right
        board[loc_x][loc_y+1] = board[loc_x][loc_y];        // value above 0 is replaced with non-0
        board[loc_x][loc_y] = 0;    // value above 0 is now 0
        return true;
    }else if (board[loc_x][loc_y-1] == 0 && (loc_y-1 >= 0)){      //check left
        board[loc_x][loc_y-1] = board[loc_x][loc_y];        // value above 0 is replaced with non-0
        board[loc_x][loc_y] = 0;    // value above 0 is now 0
        return true;
    }
    return false;
}

/**
 * Returns true if game is won (i.e., board is in winning configuration),
 * else false.
 */
bool won(void)
{

    int count_up =1;
    for (int i=0; i<d;i++)
    {

        for (int j=0;j<d;j++)
        {

            if(board[i][j] == count_up) //if equal to 1 starting
            {
                count_up ++;
                if(count_up == (d*d)-1){ //if count_up successfully adds up to the max value, means all is correct.
                    return true;
                }
            }
        }
    }

    return false;

}