Yajilin (PuzzleMadness)

About Yajilin (PuzzleMadness)

A Yajilin grid starts with only its clues: a number with an arrow, such as 2 pointing left, which says exactly how many shaded cells there are in that direction from the clue to the edge of the grid. Every cell that is not a clue ends up either shaded or part of the loop; none may be left empty. Shaded cells may not touch each other horizontally or vertically, though touching at a corner is fine. The loop is a single closed path that moves between neighbouring cells, never crosses itself and passes through every unshaded, non-clue cell.

Clues of 0 are the first help, as every cell in their direction must carry the loop; the site lets you drop a dot in such a cell to show the loop passes through before you know which way. Corner cells and cells hemmed in by shading have only two ways out, which fixes the loop locally. Today's Medium puzzle, for example, is an 8x8 grid with ten arrow clues.

PuzzleMadness is a free puzzle website run by Dewi, a software developer who started out making games for the PlayStation 2, Nintendo Wii and DS and now builds the site as a hobby. It carries dozens of puzzle types, from classic sudoku to newer logic grids, and each one gets its own dated puzzle every day at each difficulty. Yajilin comes in Easy, Medium and Hard versions plus a Mixed page, and the same day's Yajilin puzzle is shared by everyone who opens it.

The site checks your grid as you go and tells you when it is finished; it does not publish solutions. Each completed puzzle earns a score, and scores feed a monthly and an all-time Yajilin leaderboard, where only your best attempt at a puzzle counts. Older days stay in the archive, so a missed puzzle can still be played later and still counts toward the current month. Playing needs no account; a free registration gives you a username on the leaderboards and a cloud save. The pages carry adverts.

How to play Yajilin (PuzzleMadness)

1. Open today's Yajilin page on PuzzleMadness and choose a difficulty from the menu above the grid.
2. Read each arrow clue: it tells you how many shaded cells lie in the direction of the arrow.
3. Shade cells to satisfy the clues, never letting two shaded cells touch along an edge.
4. Draw one closed loop through every cell that is neither shaded nor a clue.
5. The site tells you when the grid is complete and adds your score; registered players appear on the leaderboards.

Screenshots

Tips

• Mark every cell in the direction of a 0 clue as loop; the cells next to the edge then often have only two exits.
• A corner cell on the loop must turn, so both of its neighbours carry the loop too.
• Next to a shaded cell the loop has fewer ways through, which often fixes its direction.
• Missed a day? Earlier puzzles are in the archive, and finishing one still counts toward this month's leaderboard.

Questions