I was going to check my solution to pset3 fifteen with check50 while I received two failure errors on the console (on the last 3x3 and 4x4 checks).

:) fifteen.c exists.
:) fifteen.c compiles.
:) 3x3 board: init initializes board correctly
:) 3x3 board: catches moving 8 an illegal move
:) 3x3 board: catches moving 1 as a legal move
:) 3x3 board: move blank up twice
:) 3x3 board: move blank left twice
:) 3x3 board: move blank left then right
:) 3x3 board: move blank up then down
:) 3x3 board: move up-up-left-down-down-left-up-up-right-down-down-right
:) 3x3 board: make sure none of 2, 4, 5, 6, 7, 8 move tile
:) 3x3 board: move blank left (tile 1) then up (tile 4), then try to move tiles 1, 2, 6, 8
:( 3x3 board: make sure game is winnable
    expected "Tile to move:", not "\x1b[2J\x1b[0;0..."
:( 4x4 board: make sure game is winnable
    timed out while waiting for program to exit

I really can't get the point of the failure. I double checked my solution and it seems to me that everything works fine.

This is the won() code I wrote (99 is the "_" character):

bool won(void)
    int count = 0;
    int prev = 0;
    int max_tile = (d * d) - 1;

    for(int i = 0; i < d; i++)
        for(int j = 0; j < d; j++)
            if(prev < board[i][j])
                prev = board[i][j];
                count += 1;

    if(count == max_tile -1 && board[d-1][d-1] == 99)
        return true;

    return false;


Can someone give me advice on how to fix these two errors? Thank you in advance!

1 Answer 1


Looks like it's just not finishing the game.

Let's say that d=3. That means that max_tile = (3*3) - 1 = 8. Then, the following test has to evaluate to true to register a win:

if(count == max_tile -1 && board[d-1][d-1] == 99)

It seems to me that if it's a win, then count would be 9. Then, the first test would fail because 9 does not equal 8-1.

Looks like the problem lies in the if statement. Seems like you could also get a false positive.

Just out of curiosity, what did you get when you manually tested the program???

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