This week’s mochikoro puzzle has a 15X15 grid. And I’m back to asymmetrical clues. (I tried.) The 15X15 format makes for a more difficult puzzle, both for solving and for creating. Enjoy!
The last week for the 10X10 format and I think I saved the best for last. This puzzle avoids a lot of huge islands and a lot of 1-cell island clusters. I’ll be working on a 15X15 puzzle for next week. I’ve spent a little time on it already and it seems like the larger puzzles will be more difficult to make. Without further ado, here’s this weeks puzzle:
Tomorrow, I’m hoping to have a new feature.
This week’s puzzle has fewer clues, but still doesn’t have the difficulty that I would like to see. I’m planning to try one more in the 10X10 format and then try some 15X15 puzzles.
Also, this week, I have a pdf for the mochikoro puzzle. And the solution is here.
Here’s my third mochikoro puzzle. I like this one the best, but it has more clues than I was hoping for. I managed to get the clues to be diagonally symetrical this week (which may be part of the reason why there’s so many of them.) I think that I may have over-compensated with regards to having too many large islands as you can probably tell from the clues. I continue to be interested in what kinds of number patterns leave the puzzle ambiguous and I’ll write a longer post on this next week. So, without further ado, the puzzle:
The solution is here.
Here’s this weeks puzzle. Commentary below.
I changed my algorithm slightly to build puzzles with a lower density of “land” squares and I think it was successful. There are still some tweaks I would like to make and I still do a fair bit of manual editing, but I count this week as progress over last. I’m looking to get it so that the clues come out in a nice symmetrical pattern. I’m getting closer to that too.
In any case, I’ll have another next week. Here’s this weeks solution.
I’ve decided to post some original puzzles here on puzzlinks.com. There are two reasons for this. First, what’s a puzzle blog without orignal puzzles? Second, I realized after I posted my entry on Mochikoro a while back that there are very few places to find such puzzles on the English web. So, I decided to create some of my own. As you may be able to guess from the title of this post, I’m hoping it will be a weekly feature. Right now, I’m shooting for a 20 week run.I also thought that it might be interesting, since I’m in uncharted territory a little bit, to document what worked and what didn’t in the puzzle making process. But first, the puzzle (rules for solving the puzzle can be found here):
I wrote a little algorithm to generate a map for the puzzle. I then placed the numbers myself and made some minor edits. I hope there is a unique solution. If not, someone please comment to let me know. Here’s what I learned in this iteration:
So, I have a few things to work on for next week. When I post a new puzzle then, I’ll address all of the issues above. For now, enjoy this one! And here’s the solution, if you need it.
Slither Link is a nikoli puzzle sometimes called “Fences.” Slither Link puzzles consist of a field of points in a square grid with numbers inside some of the individual squares. The goal is to connect the points to form a single loop with the constraint that each number must be enclosed on as many sides as indicated by the number. There’s a nice flash tutorial for the puzzle on the nikoli site.
I bring this up because I just came across a great collection of Slither Link puzzles through Passion For Puzzles. Also, if you’re looking for an interesting variation on Slither Link, check out last year’s US Puzzle Championship test. There’s a puzzle called “False Field Fences.” Numbers inside the loop tell the correct number of enclosed sides, while numbers outside the loop indicate an incorrect number of enclosed sides. Of course, before you solve the puzzle, you don’t know which are on the inside and which are on the outside.
I just found a collection of Heyawake puzzles, so I figured it would be a good puzzle to profile next. Heyawake is also called “divided rooms.” Like Mochikoro, Heyawake is a binary-determination logic puzzle where the goal is to determine which blocks in a grid are filled in and which aren’t. Unlike Mochikoro, Heyawake has a nice wikipedia page.
In Heyawake, the grid is subdivided into rectangular “rooms.” Some rooms have a number in the corner to indicate how many squares should be filled in for that room. Of course, there are a series of rules governing how the squares should be filled in, otherwise it wouldn’t be a puzzle. From the wikipedia site:
- Rule 1: Painted cells may never be orthogonally connected (they may not share a side, although they can touch diagonally).
- Rule 2: All white cells must be interconnected (form a single polyomino).
- Rule 3: A number indicates exactly how many painted cells there must be in that particular room.
- Rule 4: A room which has no number may contain any number of painted cells (including the possibility of zero cells).
- Rule 5: Where a straight (orthogonal) line of connected white cells is formed, it must not pass through more than two rooms—in other words, any such line of white cells which connects three or more rooms is forbidden.
The aforementioned collection has plenty of puzzles of varying difficulty. It also has a nice example, in case someone is having trouble with the rules.
At some point I will want to go through this list of Japanese puzzles on wikipedia and do a write up for all of them. For right now, I will write them up as I encounter them.
I found this blog recently that contains a few examples of a puzzle called “Mochikoro.” It’s nearly impossible to find any english web sites that feature this puzzle or have descriptions of it. In fact, at the time of this writing, neither wikipedia nor the blog I linked above has any description of the puzzle or instructions on how to solve one.
Fortunately, the blog does contain a link to a page where the puzzle is called “Archipelago” and instructions for solving are included.
The basic idea is to think of the puzzle space as made up of blocks which are either water and land. The numbered squares are land squares and are part of a rectancular island of land that contains the number of blocks indicated by the number. No 2X2 pools of water can exist in the puzzle space and all islands must be joined together diagonally into an archipelago (hence the english name.)
If you’re interested, click over to the blog and try one out. In the meantime, I might write up a wikipedia entry.
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