Pset3/fifteen: move

Question

I think some of the move code I've written is working correctly in that once the "Tile to move:" message appears and I enter a logical tile to move, I do not see the "illegal move" message, but when I do choose a number that does not border the blank space, I do get the "illegal move" message. However, the board does not redraw and the "Tile to move:" message remains after a correctly chosen tile to move.

Any hints on mistakes I've made or additions I need are very much appreciated!

    void init(void)
{
    // TODO
     int grid [d][d];
     int i = 0;
     int j = 0;
     grid [i][j] = (d * d) - 1;
     int n = (d * d) - 1;
     for (j = 0;j < d;j++)
    {
        board [i][j] = n;
        n--;
    }

    while (i < d)
        {
            i++;

            for (j = 0;j < d;j++)
                {
                    board[i][j] = n;
                    n--;

                }
    if (i == d-1)    
    {   if (d == 4 || d == 6 || d == 8)
        {   //swap 1 and 2

        int temp = board[i][j-2];
        board[i][j - 2] = board[i][j - 3];
        board[i][j - 3] = temp;
        }    

    }
}
}

/**
 * Prints the board in its current state.
 */
void draw(void)
{
    // TODO
    int i;
    int j;

    for (i = 0;i < d;i++)
    {
        for (j = 0;j < d;j++)
        {   if (board[i][j] == 0)
                printf("%2c  ",'_');
            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)
{
    // TODO
    // SEARCH for tile
    int i = 0;
    int j = 0;

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


            {   if (board[i][j] == tile) 

                   {

                    if (board[i][j + 1] == 0 || board[i][j - 1] == 0
                        || board[i + 1][j] == 0 || board[i - 1][j] == 0)
                    {   // move tile
                        int blank = 0;
                   int temp = tile;
                   board[i][j] = blank;
                   blank = temp;

                    return true;
                    }
                   }
            }               
    }
    }
    return false;
}

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

Answer 1

The code does a nice job of swapping values around between tile, blank and temp, but does nothing with the actual values in the board[][] array. The actual board remains unchanged.

While the values in tile and blank may be useful to locate the tile to move and the blank tile, you have to swap the actual array elements to execute the move.

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