# Puzzle No. 418 : Domino Sudoku [Daily League]

Firstly, PDFs!

Today’s Sudoku is just an experiment, that I think is neither great nor bad. After last week’s challenge, this should be pretty easy.

Rules – Place a digit from 1-8 in each cell of the grid so that every row, column and thickly outlined 2×4 box contain the digits 1-8. Also, in each 2×4 box, there must be 4 distinct dominos (1×2 tiles). The distinctions are – Vertical+Odd, Horizontal+Odd, Vertical+Even, Horizontal+Even. In other words, there should be two dominos of each parity, one horizontal and one vertical.

Enjoy!

P418

# Puzzle No. 417 : Tapa

I think I could settle into this Tuesday, Thursday, Sunday schedule. Tuesday is a constant with the daily league, but I feel I’ve been letting down my other-puzzle-loving-readers a bit lately. Anyway, today’s Tapa is really hard. Even apart from the intended deduction, which takes a lot of staring, there’s a few tricky little steps there. It is another one of those reserve puzzles I was talking about that I’m gonna stop saving.

Also, I qualified from the Mumbai Round of the Times Sudoku Championship. They’ve written a bit about me, but I’m quite certain looking at it you would never guess that they took a long interview. The test itself was quite fun, as would be expected with LMI as the puzzle creators. Rohan finished in 27 minutes, me in 37 apparently. I had a horrid experience last year where I went out due to 2 mistakes (missing out on a hefty bonus along the way, pushing me from a probable 3rd to a 14th), so I spent a good chunk of that 37 minutes checking my answers, and at the end was quite relieved to qualify. Another highlight of the day for me was that so many eager participants were asking about ways to follow up in the rest of the year. So if any of you are looking here, you can see the About the blog section for ways to contact me with any doubts/queries.

Overall, a good experience, as it always is when meeting people with a common interest. I now look forward to the National finals, renewing my rivalry with Rohan ( 😉 ) and meeting and competing against Rishi in person for the first time, and also the other competitors (known as well as new).

To the puzzle!

Tapa rules.

Rated – Hard.

Enjoy!

P417

By Prasanna Seshadri Posted in Hard, Tapa

# Puzzle No. 416 : Nurikabe

I’m back on my own laptop, and hopefully with no more problems to come, I’ve decided its about time I started my regular schedule again. I’ve also decided to stop keeping reserves. My laptop and an external hard disk have both stopped working in the recent past, and that just makes me too worried that my good puzzles could disappear without use, which is far worse than not being used for something special. I’ll get back to just backing my ability to write puzzle sets as and when needed.

So, here’s a Nurikabe that I’d written a good while ago.

Rules.

Rated – Medium.

Enjoy!

P416

# Puzzle No. 415 : Repeated Neighbours Sudoku [Daily League]

Firstly, PDFs!

Week 25.

Week 26.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

Today’s Sudoku is quite tough I think. It has a really narrow path with some really tricky deductions on the way. Still, I like the logic as well as the appearance I got working here.

Rules – Follow regular Sudoku rules. Additionally, each shaded cell must have repeating orthogonal neighbours (neibhbours sharing an edge). White cells must have distinct orthogonal neighbours.

Enjoy!

P415

# Puzzle No. 411-414 : UKPC 2013 Puzzles

Edit: Congratulations to Neil Zussman from UK, the overall winner.

Following up from my non-puzzle post before this, I’m still not well folks. And my laptop’s still not fixed. Overall, not a good time. I’m just hoping everything becomes fine by the time the Championships come along.

Speaking of Championships, the UK Puzzle Championship was held recently, around the same time as the IPC. I contributed 4 puzzles to the UKPC. Two of these were fairly common types, Nurikabe and Corral. I had been doing many Kurotto and Yosenabe puzzles around this time, Yosenabe in particular seemed fresh, so I used that and themed a UK into it, adding to my other UK themed puzzle, the Corral. For the other puzzle, I actually wanted to do either a snake variant or a true-false type puzzle. As is usually the cases with me I just ended up combining both and we have True-False Snake.

Anyway, to the puzzles, (with points as they were awarded to each during the UKPC).

P411: Nurikabe. 15 points.

P412: Yosenabe – Move all circles, vertically or horizontally, so they enter the grey areas. Show the movement of a circle by an arrow, with the tip of the arrow in the first cell it enters of its grey area. Arrows can cross through grey areas if they need to reach a grey area beyond. The arrows do not bend, and do not cross other white circles or lines of other arrows. The number in a grey area must be equal to the sum of the numbers of the circles which enter the area. Empty grey areas may have any sum total, but at least one circle must enter each grey area. Example with solution. 20 points.

P413: Corral. 20 points.

P414: True-False Snake – Draw a snake in the grid of unknown length. The head and tail of the snake are given. The body of the snake cannot touch itself, not even diagonally. The numbers indicate the number of cells the snake visits in the direction of the arrow. If the snake does not pass through a clue cell, then that clue is true, otherwise, it is false. Example with solution. 40 points.

Enjoy!

P411

P412

P413

P414

# A few updates [Non-Puzzle Post]

Regular readers of this blog might be wondering why I haven’t gone back to my regular schedule like I said I would, and didn’t even post a Sudoku for the Daily League yesterday, instead asking someone else do so, after which Karel kindly stepped up.

My past week has been bad. First, my laptop starts crashing and I need to give it for servicing. The servicing has costed quite a lot, and I’ll be getting my laptop back tomorrow, maybe. Then, I fall ill. It started off with just little things and suddenly escalated yesterday, leaving me in quite a bad state. Its gone as quick as it came though, and today I’ve almost recovered, and its back to the little things. I’ve still decided to prolong my break (from everything) though, just to be safe. But, I’ll still be updating my PADE page because that takes minimal effort as far as actually creating the puzzle goes (the challenge is mainly in thinking up a link to that day’s theme), there’s some nice easy puzzles there.

I knew about PADE through Indiblogger and there is now Indian Blogger Awards that’s been organized by them. I’ve nominated this blog there, and if you want to say something about it, go right ahead.

Also, a few competitions have been announced. In chronological order,

The Times Sudoku Championship, in partnership with LMI, will be held across 4 cities, selecting 4 winners. The final 16 then compete in the finals and the 4 winners there will form the team representing India at the World Sudoku Championship 2013 in China.

The Indian Sudoku Championship, hosted solely by LMI, will be held online on 10th August, and will be used to decide the official Indian Sudoku Champion. The winners here can also opt to represent India at the World Sudoku Championship, in an individual capacity (unless the winners merge with those of TSC of course).

I hope to build on my IPC win with good finishes in both of these events. I also hope to get over my disappointment of not making the finals of the TSC last year…

# Puzzle No. 410 : Frame Sudoku [Daily League]

Edit:  Week 24 PDF.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

Today’s puzzle is a normal enough. About a medium difficulty. I just thought I’d theme it around the date of the IPC. The results are now publicly available here. I have a total of 977.5 points, having finished with one mistake. A healthy winning total I think. Indians who have participated (or want to participate in future years) should also check the forum discussion about the IPC here and let the organizers know their opinion too.

Anyway, back to the Sudoku.

Rules – Follow regular Sudoku rules. Additionally, a clue outside gives the sum of the first 3 numbers in that direction.

Enjoy!

P410

# Quick IPC update [Non-Puzzle Post]

In case you’ve not heard yet through the forum discussion or through facebook, the official part of the Indian Puzzle Championship is over. For the first time, I am the champion ( 😀 ), followed by Amit Sowani, Rajesh Kumar, Rohan Rao in that order. I can’t put any more details while its still open for International participation. I’ve written my opinions on the forum, they can be seen if you’ve participated. I’ll maybe copy them and add a bit more detail here once its fully over.

Otherwise, I’ll be back to normal blogging schedule. Expect a Sudoku on Tuesday for the Daily League and some puzzle posts after. As with the practice, anyone can feel free to ask me a bit more details on how I approached certain puzzles here.

# IPC Preview – Practice, Solving Tips, Links

Update: Fixed the typo in Pentomino Kakuro. New PDF uploaded. No other change.

Update: There is an erratum published on the IPC site that says the 2×2 restriction applies to Happy Dots too. Since the practice puzzle in the PDF still gives a nice practice for placing the dots and forming regions, and only uses 2×2 regions minimally, it stays the same in the PDF. We’re sorry for the inconvenience.

If you’re having trouble with some puzzles, seeing/adding to the discussion in the comments might help. (This also serves as a spoiler alert for those who want to work on the puzzles without help)

Right, took a while, but we’re finally there. If you’re still not aware, the Indian Puzzle Championship will be held on 7th July. Here are our (me and Swaroop) best efforts, with the main goal being to try to help the newer participants.

This PDF features –

1. Practice puzzles for B1, B2, C, D, E2, F1, F2, G2, I1, I2, J1, J2, K1, K2, L1, L2, M2.

2. Beginner-level solving tips for all the puzzles in the set.

3. Solutions to all the puzzles in the set.

4.  Links to other practice material, pattern guides, and other technical tips.

Enjoy!

# Puzzle No. 409 : Point-to-Next or Search-9 Sudoku [Daily League]

Firstly, PDF!

Week 23.

Also, IPC Practice puzzles will be posted on this and another blog shortly, hopefully by tonight, but latest by tomorrow.

Not much to say about this hybrid, except that it might be a bit tricky. Note the part in bold.

Rules –

Follow Sudoku rules. Additionally, each clue will describe exactly one of these two behaviors.

1. If digit ‘n’ is placed in a cell with arrow, digit ‘n+1′ must be placed in one of the cells pointed by the arrow.

2. The arrow points at the 9 in that row or column and the number in the cell with the arrow is the distance from the cell to the 9.

Both restrictions cannot apply for the same arrow.

Enjoy!

P409