Break over

Not that I'm likely to go back to a regular publishing schedule, but it'll hopefully be more frequent than the past few days. If it's any consolation, I have been writing puzzles for a different medium this week, and some of them may find their way here eventually.

Anyhow, on to the rules for today's puzzle: Place the 12 free pentominoes onto the blank space in the grid. Numeric clues indicate the number of pentominoes in the 8 adjacent cells.

Reflect link

Another Nikoli experiment. Draw a loop joining orthogonally adjacent cell centres. All points where straight loop segments intersect are given as crosses, and must be visited. The loop may not touch itself (stop sniggering) at any other point or way. The loop must visit all cells with triangles, and must turn at those points. Some of these triangles may be marked with a number, which indicates the total number of cells visited by the straight loop segments meeting there.
I have never actually seen one of these problems before in any medium, so I have no idea how close these are to the typical problem of this sort. The first one is an easy introduction to the rules, the second one is just a bit meatier.


I have to say I love this puzzle's name. The rules of ShakaShaka are kind of odd, so read carefully. I'm rather fond of this one: the logic flows smoothly, it's nicely Q-shaped for a similar commemorative reason to a prior puzzle (minus the drink), and didn't take forever to make.

A little lightup.

Akari, or light up, is a popular Japanese puzzle (rules). This one is easy-ish.

Hidden Halfgrid

Draw a loop that contains exactly half the grid by connecting orthogonally adjacent dots. All cells with the same letter have the same number of sides used by the loop. All cells with different letters have a different number of sides used by the loop. Packs a decent punch for the size and clue density. And yes, I win no points for elegance.

Had enough of Masyu yet?

I for one am sated for the moment. This one is difficult.

Masyu 3 - now with added pzv

(Rules). Medium, I guess. There's a uniqueness fix that I'm not too crazy about in there.

You may notice that clicking on the picture brings up the wonderful site, where you can solve the problem online. I was considering the much more capable applet, but board entry is currently manual, and the Java requirement means some users will miss out.

Easy Masyu

Antisymmetry is the hip Masyu thing everyone else does better. This one is rather easy.


Count triangles of all sizes in the picture. This is one of those things that is achievable in either a minute or an hour, depending on prior experience. Since it's rather hard to verify one's own answer for this sort of activity, I'm going to spoil the puzzle for lovers of Early Byzantine history: the answer is the year Gainas fled from Constantinople.

Local fun

I participated in a local Sudoku tournament yesterday, and won myself some drink I'll have to pass to someone. Turns out there are pleasant, dedicated and organised puzzling folk nearby, which was news to me. Let me clue their name in an event-appropriate way:

Ice Barn 2

(Rules). Less pretty, but more meaty than the previous one.

Another Pentomino tiling.

For once, looking where to put Xs won't help much. Otherwise, everything from the previous post applies.

2 grids, 4 minutes

Get your stopwatches out, read under the fold, and fill these two sudoku grids in four minutes or less.

Welcome to the Ice Barn

Ice Barn is a rather rare Nikoli type. Rules go something like:

Draw a directed path from IN to OUT, visiting all the ice barns (grey areas) along the way. You move from cell centre to adjacent cell centre in an orthogonal fashion. You may not backtrack, overlap or branch. You may not turn inside a barn. Crossing your path is only allowed inside barns. In some puzzles, parts of the path will be given; an arrowhead on them indicates direction of movement along them.

I've got some nerve publishing this: I wrote this a couple of hours after learning this puzzle type existed. The solution is more symmetric than the grid, so I think that's obvious.

I have to say I love the Japanese naming connotations. Ice, because of the sliding inside presumably. And barn, because, um... , that's where you usually revisit your past actions? Or keep your ice, for that matter.


Aka Hashiwokakero (rules in German and English).

Pentomino tiling

Cover the white cells of the grid with one of each of the 12 different free pentominoes. This shape is uniquely tiled on its own, but you will likely have more fun if you use the clues. The clues on the top and left specify the number of pentominoes in that row / column. Any pentomino on a row / column with a clue to its right/bottom covers at least as many cells of that row / column as the clue.