Puzzle 90: Antimatter

Dual Masyu Follow regular Masyu rules. This is a loop puzzle: Draw a loop that passes some of the cells such that the loop never touches or crosses itself, the loop only turns on cell centers, and the loop only makes 90-degree turns. The loop must pass all circles. When it passes a white circle, it must go straight, but must turn either before or after (or both). When it passes a black circle, it must turn, but must go straight both before and after it.

Additionally, this puzzle is two in one; it has two solutions that are coupled in the following way. Gray circles are two circles that have different colors in the two puzzles; if a gray circle acts as a white circle in one puzzle, then it must be black in the other, and vice versa. (In either puzzle, two gray circles may act as one white and one black; they don’t need to act as the same color.)

Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published

Puzzle 90: Antimatter
Dual Masyu

No particular comment; just toying with interesting things.

Puzzle 89: Three-Four-Five

Fillomino Read here for instructions.

Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published

Puzzle 89: Three-Four-Five
Fillomino

Just a classic Fillomino to fill my blog. No particular reason of why I have that theme; I was constructing the opening and saw that I only used the digits 3,4,5, so I went ahead and set it as the theme. Also, it took me more time to get the particular ending I wanted… Spoiler: [If the place rotationally symmetric to where you did the opening is also where you feel like doing the same trick again, then you get my intention. And yes, I wanted to force both the bottom-left and top-right corners to end in that way.]

Now back to doing homework.

Puzzle 88: I Give Up

Masyu Loop: Draw a loop that passes all the circles. Whenever the loop passes a white circle, it must go straight, but turns either before or after the circle (or both). Whenever the loop passes a black circle, it must turn, but go straight on both before and after the circle.

Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published

Puzzle 88: I Give Up
Masyu

This puzzle was intended to be completely antisymmetric and has the same (okay, mirrored) pattern of givens as this puzzle. Turns out both objectives aren’t met. I give up tweaking it, hence the name.

Puzzle 87: Jagged Squares

Futoshiki Latin square: Put a number between 1 and 6 into each cell inclusive such that each row and column contains exactly one instance of each number. The grid has inequalities in it, which must be satisfied by the numbers in the corresponding cells.

Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published

Puzzle 87: Jagged Squares
Futoshiki

Just to put some content in, ugh.

Puzzle 86: Scarcity

Pure Loop Loop: Draw a loop that passes all white cells and no black cell such that the loop goes horizontally or vertically at all times and never touches or crosses itself.

Expected difficulty Easy • Answer • Comment/E-mail if you want a solution to be published

Puzzle 86: Scarcity
Pure Loop
(click to enlarge)

Page 12 of Chessics #12 states that a 8×8 Pure Loop puzzle only needs four black squares to assure uniqueness of the solution, and page 143 of The Games and Puzzles Journal #8-9 states that with an addition of rows and columns (and black squares), the solution can be extended. However, I don’t find anything about how many extra black squares are necessary, so here I’ll give an upper bound: a Pure Loop needs at most black squares to ensure a unique solution. In fact, the result can be generalized to a rectangle: a Pure Loop needs at most black squares to ensure a unique solution (although obviously this is weak if is small compared to ). Is there anything stronger?

Puzzle 85: Loose Strands

Pure Loop Loop: Draw a loop that passes all white cells and no black cell such that the loop goes horizontally or vertically at all times and never touches or crosses itself.

Expected difficulty Hard • Answer • Comment/E-mail if you want a solution to be published

Puzzle 85: Loose Strands
Pure Loop

There we go, the last of the series. Of course, the blog is turned off again for the moment, at least until I manage to construct more puzzles. I’m busy too, you know. (By the way, expect things.) Answer key would be “lengths of horizontal segments in row/vertical segments in column” for R1/C2 (or R2/C1 or something).

Another difficult “opening”. Also for some reason I find sudden interest on Pure Loop and Heteromino now, like exploring two untouched lands… (Okay, I think I see it being used in more things now, but still.) Did you know that Heteromino almost got into FAST (as an uninteresting 3×3), but Deb decided it was too obscure and got replaced with Kakuro, which in turn also got replaced by Next Term? The more you know.

Did I ever say my computer broke like a month or two ago?

I think I forgot to say that here. To be precise, it started from like late January to February; fixed it by buying a new hard disk altogether on 21 February, thus having all my data lost. This includes a good amount of my puzzle images (I still work with Excel, yes, and that single worksheet went away), a good amount of Word documents (I usually have my PDFs published elsewhere, but without the Word it’s going to be some pain to rewrite them in case I want to edit–I’m too perfectionist sometimes), and other things.

Lesson: Back up.

Meanwhile, I’ll point you at this insanity. I haven’t matched that in terms of presentation (although I think I made a couple of insane variants, trying to match other works). Sooo… We’ll see if I have time to squeeze out something. Hey, I’m busy with college life + a future LMI test + Mystery Hunt + [insert other things here]…

Puzzle 84: Chopsticks

Hashiwokakero Draw some bridges connecting the islands (circles). Bridges can only run horizontally or vertically, and all islands must be connected (it must be possible to visit any island by using the bridges). Bridges cannot cross each other. Between any two islands, there may be at most two direct bridges connecting them. A number on an island gives the number of bridges connected to that island.

Expected difficulty Hard • Answer • Comment/E-mail if you want a solution to be published

Puzzle 84: Chopsticks
Hashiwokakero

Because “hashi” can mean “chopsticks”. Fourth of the rejected series for FAST. The answer key would be “write 1 for every single bridge and 2 for every double bridge that crosses/goes along the marked rows”, with the two bottom rows as marked.

This is probably hard because you need to observe for the opening, a bit like the dreaded Hitori. Afterwards, I’d put it no more than a medium. And I hate making Hashi’s solution image; just check that answer when you’re done or something and guess how I made it.

Puzzle 83: Division

Star Battle Put two stars in each row, column, and region bounded by bold borders. A star occupies a cell, and no two stars are adjacent.

Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published

Puzzle 83: Division
Star Battle

Third in the reject series. There was Star Battle in the original draft of the puzzle, and it’s not that trivial to solve the second part. (Of course, the answer key would be “enter the column number of the leftmost star in each row”.)

Also, apparently I start to construct puzzles on my computer too, instead of using my book again. This is what happens if you have too much access to computer. (Compare: a year ago I’m still at school, without computer access, hence why I use the book to store my puzzles.)

Puzzle 82: 5×10

Heyawake Dynasty-style: Shade some cells black so that no two black cells are orthogonally adjacent and all white cells are connected. A number inside a black bordered region—a room—indicates the number of black cells in the room. A run of contiguous white cells in the same row/column cannot span over two room boundaries.

Expected difficulty Hard • Answer • Comment/E-mail if you want a solution to be published

Puzzle 82: 5×10
Heyawake

Second rejected puzzle. As you can guess, some of the top rows would have become the answer keys, and the bottom part I still can’t figure out a logical solution for.

Three more to come. Also the ordering of how these puzzles appear is determined indirectly by Yoshiap, whose I simply asked “give a permutation of 1,2,3,4,5”. 😛