# All entries for Friday 25 June 2010

## June 25, 2010

### Friday Puzzles #58

This week dear readers, I am appealing to you for a little feedback. It seems every puzzle designer worth their salt has their own pet sudoku variant they’ve created, nurtured and loved. Oh the long days I looked on in envy!

Anyhow, today that all changes as I’ve come up with something that is (a) original to the best of my knowledge and (b) isn’t totally lame. I call it Sudoku Islands. The idea is basically a hybrid of sudoku and nurikabe. You have an NxN grid, and the idea is to fill in each column, row and box with the digits 1-M, where M < N. Moreover these digits form a connected region of the grid, with no 2×2 blocks, which surround islands. The size of these islands is clued by the grey squares, and there is exactly one given clue per island in the solution. Unfortunately if you are used to nurikabe much, the roles of white and grey (black) squares have become reversed, but you’re playing by my rules now so I guess that’s hard cheese!

What you get is in my mind something that works out to be an improved version of extra space sudoku, where you not only have to fill in the grid, but also have to work out where the extra space is. That’s all beginning to sound a bit wordy, so here’s a really easy toy example for you to get the idea. Fill this grid with digits 1-4 in each row/column/box:

#068 Sudoku Islands – rated very easy

[Solution]

And this one with digits 1-5. Enjoy!

#069 Sudoku Islands – rated medium

All puzzles © Tom Collyer 2009-10

## Information

Welcome to the blog of current UKPA sudoku champion, two-time Times national sudoku champion and general logic puzzle fan Tom Collyer.

Home of the original Friday Puzzles, each Friday I publish a 100% original and handmade logic puzzle, inspired by the world-famous Nikoli company.

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## Search

• I like the appearance of the solution. :P Nice one. by Prasanna Seshadri on this entry
• I think I've seen something vaguely similar in some of Palmer's puzzles as well. To be honest I've a… by on this entry
• That's two puzzles in a row where I find something I had used before. I know, not plagiarism; just g… by Bram on this entry
• Kota, that's not really true. I had made my puzzle before going to the WPC already. Also I don't hav… by Bram on this entry
• About 20 minutes, after restarting from a mistaken conclusion. by Bryce Herdt on this entry