## 4-5 Sudoku

For fans of Killer Sudoku, Samurai Sudoku and other variants

### 4-5 Sudoku

Can anybody create a good 4-5 puzzle?

Bill Smythe
Smythe Dakota

Posts: 564
Joined: 11 February 2006

It isn't easy to make an interesting example for this type: 3 line-box/box-line interactions or a single turbot fish near to the end is the only difficulty I can build in such a puzzle. Both are not really a challenge.

Pyrrhon
Pyrrhon

Posts: 240
Joined: 26 April 2006

Some of us don't even know, or want to know, what a turbot fish is, or an X-wing or a flying turtle kite or any of those other things, either. Feel free to take it down a notch and create a slightly less challenging puzzle for the rest of us.

Bill Smythe
Smythe Dakota

Posts: 564
Joined: 11 February 2006

Okay, here you have an example, but don't say, that it is to easy.

Pyrrhon

Pyrrhon

Posts: 240
Joined: 26 April 2006

When you work it down to the final 9 cells (yes, and 4 more 4s and 5 more 5s to fill in), you need a turbot fish to complete it (there is an another one which works the same)...

Solution

Clear the numbers (but keep the colours), now you have a grid for an odd/even sudoku!
udosuk

Posts: 2698
Joined: 17 July 2005

In the same league as 4-5 sudoku also plays the 1-2-6 sudoku. Simple steps. In the hardest cases a turbot fish near to the end. (in the last variant with three different values I can spot (the 1-3-5 sudoku) I haven't found an example which uses more than naked and hidden singles.

Here an example of the 1-2-6 variant (you must have one 1, two 2's and six 6's in each row, column and box):

Pyrrhon

Posts: 240
Joined: 26 April 2006

Pyrrhon wrote:Okay, here you have an example, but don't say, that it is to easy. ....

You're right, that one was childishly simple, wasn't it? -- even for us recreational solvers, who can usually solve Monday's, Tuesday's, and Wednesday's puzzles on the train into work, but who require a little more effort for Thursday's and Friday's.

I suppose 3-6, 2-7, and 1-8 would be just as mickey mouse, maybe even more so. (How about 0-9? )

Bill Smythe
Smythe Dakota

Posts: 564
Joined: 11 February 2006