re'born wrote:claudiarabia wrote:This puzzle is a work of 2 Minutes. With SE 7.2 it is not to time-consuming in solving and I like the simple diagonal pattern because it looks so vivid.

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`. 3 . . . 5 . 7 . `

. . 9 . . . . . 8

1 . . 6 . . 2 . .

. . 4 . 8 . . . 5

. . . . . 7 . . .

6 . . . . . 3 . .

. 7 . . . 2 . 9 .

. . 5 . . . . . 1

8 . . 1 . . 4 . .

Claudia

Actually, despite the 7.2 rating, this seems to be a very tough nut to crack. In fact, this might be one of the hardest 7.2's I've seen (unless I'm missing something obvious). And you say that you constructed it in 2 minutes? Bravo, Claudia!

You are totally right. The solving was much more complicated than the comstruction. But in the end it was worth it. In the end I needed 10 forcing chains in addition to the other techniques for solving it, while the explainer needed 21 chains. Interesting was the fact that I could use many trunks of forcing chains for new forcing chains eliminating candidates in the same way. And I found a forcing chain which showed that two numbers would have to be placed in one cell which is impossible. Usually I discover forcing chains, where some cells stay empty.

For the first time I found also a forcing chain which I could connect with an xyz-Wing which, at the end of the chain, eliminated a crucial candidate.

The cycles where almost the same which showed the explainer with a slight theoretical difference I will explain in a cycle thread another time.

Interesting also that the X-Wing I found is exactly the same like in the SE without knowing it's solution. I always thought in such complicated sudokus, ways differ much and it would be impossible that I come to the same X-Wing after 7 Forcing Chains and one Cycle.

Claudia