pset3: check50 sad and frawn yet to me the functions are okay

Question

https://gist.github.com/fb943980ec3ee81f98d9ff6ff1b4cfef

Sorry for the readers. I tried formatting the code and text but was unable.

Any help will be appreciated too.

:) init initializes 3x3 board correctly
:( init initializes 4x4 board correctly
   \ expected "1" character 3 of line 4, not "2":( 3x3 board, move blank up twice
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move blank left twice
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move blank left then right
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move blank up then down
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move up-up-left-down-down-left-up-up-right-down-down-right
   \ expected prompt for input, not exit code of 0
:( 3x3 board, from start try to move tile 2, 4, 5, 6, 7, 8
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move blank left (tile 1) then up (tile 4), then try to move tiles 1, 2, 6, 8
   \ expected prompt for input, not exit code of 0
:( 3x3 board, move blank up (tile 3), then try tile 2
   \ expected prompt for input, not exit code of 0
:| 3x3.txt wins the 3x3 board
   \ can't check until a frown turns upside down
:| 4x4.txt wins the 4x4 board
   \ can't check until a frown turns upside down

---

void init(void)
{
    // TODO
    int k=(d*d)-1;
    for(int i=0;i<d;i++)
    {
        for(int j=0;j<d;j++)  
        {
            board[i][j]=k--;  
        }
    }
    if(k%2==0)
    {
        if(board[d-1][d-3]==2 && board[d-1][d-2]==1)  
            me_swap(&board[d-1][d-3], &board[d-1][d-2]);
    }
}

---

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

    for(int i=0;i<d;i++)
    {
        for(int j=0;j<d;j++)  
        {
            if(board[i][j]==0)
            {
                printf("_  \t");       
            }
            else
            {
                printf("%2d \t ",board[i][j]);  
            }
        }
        printf("\n");
    }
}

---

/**
 * If tile borders empty space, moves tile and returns true, else
 * returns false. 
 */
bool move(int tile)
{
    // TODO
    int blank_space=0;
    for(int i=0;i<d;i++)
    {
        for(int j=0;j<d;j++)  
        {
            if(tile==board[i][j] && tile<(d*d-1) && tile>0)
            {
                if(board[i-1][j]==blank_space)
                {
                    me_swap(&board[i][j],&board[i-1][j]);
                    return true;
                }
                if( board[i][j-1]==blank_space)
                {
                    me_swap(&board[i][j-1],&board[i][j]);
                    return true;
                }
                if(board[i+1][j]==blank_space )
                {
                    me_swap(&board[i][j],&board[i+1][j]);
                    return true;
                }
                if(board[i][j+1]==blank_space)
                {
                    me_swap(&board[i][j],&board[i][j+1]);
                    return true;
                }
            }

        }

    }

return false;
}

---

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

---

//call swap when in need to
void me_swap (int *a, int *b)
{
    int temp=*a;
    *a=*b;
    *b=temp;
}

Answer 1

It seems you are mixing up the value of a tile and its coordinates. Let's say the tile in row 1 column 3 has the value of 2. Then board[1][3]=2. So the following line from your code makes no sense:

if(tile==board[i][j] && tile<(d*d-1) && tile>0)

You make the same error throughout, and you also make the same error with blank_space. What you want to do is store the row and column coordinates of tile and blank space as tile_row, tile_column, etc.

Note that you are using the correct approach in your won() function.

Once you do that, you can just switch the value of board[i][j] directly without using pointers in swap_me if desired.