Workshop › 15 Puzzle › Step 11 of 27

The solved board from N

What we are doing

Instead of typing sixteen numbers, solvedTiles() builds the solved board from N. We will need it again to check whether the puzzle is solved.

```js
const solvedTiles = () => [...Array(N * N - 1).keys()].map((i) => i + 1).concat(0)

function reset() {
  tiles = solvedTiles()
}
```

What it means

• Array(15).keys() counts 0 to 14; [... ] puts those numbers in an array.
• .map((i) => i + 1) adds one to each: 1 to 15.
• .concat(0) adds the gap at the end.
• Each call builds a new array, so changing tiles never changes the "solved" list.

Your turn

1. Under colOf, write the solvedTiles line.
2. In reset, replace the long list with solvedTiles(). Press Run.

Skills: Arrays and objects

← Draw again and again Neighbours →

All steps

1. A board in one list
2. The canvas and the pen
3. Paint the table
4. A function that draws
5. Row and column
6. Where each square is
7. Draw one tile
8. The number on the tile
9. All the tiles
10. Draw again and again
11. The solved board from N
12. Neighbours
13. Slide a tile
14. Click a tile
15. Arrow keys
16. Count the moves
17. Shuffle with real slides
18. Which boards can be solved?
19. Is it solved?
20. Remember the slide
21. Count the frames
22. Smooth sliding
23. Solved!
24. Show the win
25. Play again
26. A record to beat
27. Build it yourself: a timer