Friday Puzzles #302

Here's a puzzle I don't believe I've posted publicly yet, but I think might be interesting to solve.  X-Sums Sudoku has some clues outside the grid indicating the sum of the first "X" numbers placed in cells in the corresponding direction, such that "X" is the number placed in the closest cell. For example an outside 3 means the numbers placed would be 2 followed by 1.

Enjoy!

    #343 X-Sums Sudoku – rated hard

All puzzles © Tom Collyer 2009-19.

Friday Puzzles #301

Skyscrapers Sudoku this week.  (I haven't got around to my backlog yet).  Numbers represent heights of buildings, where bigger numbers block smaller numbers.  Clues outside the grid indicate how many different buildings are visible.

Enjoy.

Edit: previous version had an error.  Hopefully that's fixed now.

    #342 Skyscrapers Sudoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #300

How appropriate to celebrate a nice round number by being nearly-but-not-quite late!


Clues outside the grid indicate the "property" of the first two numbers placed in the corresponding direction.  Odd=1,3,5,7; Even=2,4,6,8; Big=5,6,7,8; Small=1,2,3,4.

Enjoy!

    #341 Odd-Even-Big-Small Sudoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #299

I've got a backlog of puzzles that will hopefully be unleashed either later today or else next week.

This one is x-sums.  The clues outside the grid indicate the sum of the first X placed numbers in the corresponding direction.

So for example a clue of 6 could have X=2, in which case the second placed number would have to be 4.  Or, it could have X=3, in which case the second and third placed numbers would have be to 1 and 2 in some order.

Enjoy!

    #340 X-Sums Sudoku – rated easy

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #298

I've run out of time to add the final polish, but there should still be enough here to keep you busy.  Cages are clued with the sums of numbers to be placed inside them; no repeats within cages.

Enjoy!

    #339 Killer Sudoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #297

Non-Consecutive Sudoku this week.  Cells that share an edge are not allowed to contain consecutive numbers.

Enjoy!

    #338 Non-Consecutive Sudoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #296

Odd sudoku this week.  Only odd numbers are allowed in the shaded cells.

Enjoy!

    #337 Odd Sudoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #295

The difficulty this week is turned down a little.  Enjoy!

    #336 Windoku – rated medium

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #294

This one is fairly tricky too.  Enjoy!

   #335 Diagonal Sudoku – rated hard

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #293

Yes it's not Friday any more.  This should keep you busy for a while!

   #334 Irregular Sudoku – rated hard

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #292

Can you tell what it is yet?  Small packages can still sometimes pack a punch!

1 to 7 once in each row and column, and at most once in each 6 cell region.  Enjoy!

    #333 Deficit Sudoku – rated hard

(A fixed version of a previous puzzle)

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #290

So I think for 2017 this blog may well be just sudoku and variants - however I will be posting links to Grandmaster Puzzles as and when my puzzles there get published.

Lets see how it goes, dearest reader.  As ever, hope you enjoy!

    #331 Sudoku – rated easy

All puzzles © Tom Collyer 2009-17.

Friday Puzzles #289

Better late than never - and even better when the puzzle isn't broken - here is a Sum Sandwich Sudoku.

Rules: Apply classic sudoku rules.  Additionally, the clues outside the grid indicate all numbers placed in the corresponding direction that are the sum of the numbers placed in the two neighbouring cells in that direction, e.g. 132.  If a number is not clued outside the grid, then it must not be the sum of its two neighbours in that direction.

Enjoy!

    #328 Sum Sandwich Sudoku – rated medium

All puzzles © Tom Collyer 2009-16.

Friday Puzzles #288

That moment when you realise Christmas Day is also a Friday!

Nothing too taxing today as this was rather a last minute affair, but watch your step!  Each of the four shaded regions follows a different rule:

• odd
• even
• fortress
• renban group

Merry Christmas to all my dearest readers, and as ever, enjoy!

EDIT: I'd managed to leave a couple of clues out.  This should make things a little easier!

    #328 Mini-Matchmaker Sudoku – rated medium

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #287

Greetings all!  I've been a bit busy recently - not least because I have taken over the role of Competition Director of the WPF's Sudoku GP.  Exciting times indeed.

I have been posting for the Daily League once a fortnight for a while, as has Bastien on a Wednesday.  I think this means now at least we are posting on different weeks.  By-the-by, if you fancy yourself as an aspiring Sudoku author, then please do contribute!

Anyhow, only time for a classic this week.  Enjoy!

    #327 Sudoku – rated easy

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #286

Well, I hope this was worth the wait.  I'm quite pleased with this one - Enjoy!

    #326 Very Odd Sudoku – rated easy

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #285

In celebration of George Boole's 200th birthday, and Bram de Laat's excellent Clone Or Extra Region Sudoku, I give you Clone And Extra Region Sudoku.  Enjoy!

Rules: the two shaded regions contain each of the numbers 1-9 exactly once.  Moreover, the same numbers go in cells with the same relative position in the two regions.

    #325 Extra Region And Clone Sudoku – rated hard

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #283

Well I've been and gone to the world championships in Sofia, Bulgaria.  Expect some kind of write up in the next week-ish, although I'm not sure I have the heart or energy to go into the kind of detail I normally do.

Abbreviated results are:

WSC: 49th -- GBR-A: 8th
WPC: 45th -- GBR-A: 7th

I'm pretty happy with both sets of team results, just about happy with the WPC result and pretty disappointed with the WSC result.

Congratulations to our two new Japanese world champions Kota Morinishi (WSC) and Ken Endo (WPC).  Japan and Germany won the respective team competitions.

A new fixture during world championship week are the two WPF Sudoku and Puzzle GP finals.  I still have a few thoughts about these competitions which I will save for another post, but as a UK author for the 8th leg of the Sudoku I also had the honour of contributing two puzzles for this play-off.

One of them was a classic, which got selected.  Nothing hugely special, but it was probably at a medium difficulty level as opposed to my normal easy level.  I was a little disappointed that my variant didn't get picked, which was a hybrid Renban-Killer variant.  So instead I get to share it here with all my dearest readers!

Rules: numbers placed in cages don't repeat and sum to the given clue.  Numbers placed in shaded regions don't repeat and form a consecutive set.

Enjoy!

    #323 Renban-Killer Sudoku – rated hard

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #282

I must say I feel even more under-prepared for the upcoming world sudoku and puzzle championships than I was for the comparative cake-walk that was the Times championship.

Hopefully this is a good omen.  Sadly it's not that great an omen for puzzles I've been writing recently.  The rules of anti-diagonal state that you can only place 3 different numbers on each diagonal.

Enjoy, anyway!

    #322 Anti-Diagonal Sudoku – rated easy

All puzzles © Tom Collyer 2009-15.

Friday Puzzles #281

A couple of pieces of bookkeeping firstly this week.  Firstly, last Saturday I managed to simultaneously not have a brain-freeze or make a mistake that I didn't catch, and in doing so took my 3rd Times Sudoku championship.  The write-up in the newspaper on Monday was spectacularly mediocre, and to make matters worse none of the puzzles were actually published.

To put this right, I will be putting together a trademark championship report.  I also have copies of the puzzles from both preliminary sessions, but if anyone happens to have the grand final puzzles I would certainly be interested in seeing those again.

Next piece of bookkeeping is I've been toying with a few hitori ideas this week, prompted by this excellent post on the UKPA forums.  Maybe I'll go with that for next Friday.

Anyhow, onto this week's puzzle, less than half an hour late!  Enjoy...

    #321 WINdoku – rated medium

All puzzles © Tom Collyer 2009-15.