You Asked For It!

As promised, I just posted a puzzle with the rating that is currently in the lead in our poll. And that, apparently, is INSANE. This puzzle requires all Killer techniques + it requires some advanced classic Sudoku techniques (match subsets etc). It does not require trial and error! I hope someone will solve it without the aid of a computer. To be honest, I don’t plan to post many puzzles with this difficulty – it’s dangerous for your mental health! I am surprised that according to the comments, people thought that yesterday’s puzzle wasn’t easy – all it requires for solving are innies/outies and nothing else. Although, if you haven’t practiced your outies you might find it more difficult. For instance, look at the first two rows. The sum of all cells in them must be 90. But the cage that belongs to nonet number 1 and is marked with 8 contains an outie for the first two rows! So you add up all the cages from the first two rows, find that their sum is 96 and therefore find that R3C3 must be 96-90 = 6. There are 8 (but they solve 10 cells) innies/outies in yesterday’s puzzle altogether. If you don’t find all of them – you can’t solve the puzzle. I also posted a 4×4 Classic Sudoku for the weekend. Don’t forget about tomorrow’s Saturday extra special – Samurai X – the only place on earth you can find them!
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12 Comments

  1. Steve C
    Posted October 28, 2005 at 11:25 am | Permalink

    Re Insane 28.2.05. Completed in about 15 mins, am I missing something?

    956|437|182
    712|869|354
    834|521|697
    ———–
    573|214|869
    698|753|421
    421|986|573
    ———–
    149|678|235
    287|345|916
    365|192|748

  2. udosuk
    Posted October 28, 2005 at 6:10 pm | Permalink

    Yep, using a program and manipulating with candidates I solved it using similar time. But I suppose that’s not the point. I think to make it really insane at least x-wing or swordfish should be required.

    Also, knowing that the biggest cage you can have is of 9 cells, I haven’t seen a killer puzzle with a cage in the ring shape of 8 cells, or a “broken ring” shape of 7 cells. If a “ring” lies across nonets, the cell which is enclosed in the middle could equal to one of the cells on the ring. That way we could have quite a lot combinations, for example:

    xx|x
    x5|x
    –+-
    xx|x

    3 of these x’s could be 5. So this cage of 8 x’s need not to sum to 40, and can range from 36 to 44.

  3. udosuk
    Posted October 28, 2005 at 6:16 pm | Permalink

    Alright, first didn’t mentioned Steve C’s mistake on the date (it should be Oct 28 not Feb 28).

    Also, seeing that djape does not like to have singleton cages, my suggestions could not be adopted unless he’s willing to drop this restriction…

  4. Cathy
    Posted October 28, 2005 at 6:58 pm | Permalink

    Took me about 20 minutes – can’t say this one should really be classified as insane. On the other hand, I still haven’t solved last Friday’s IQ – only got 3 entries!

  5. Cathy
    Posted October 28, 2005 at 7:00 pm | Permalink

    BTW – I did it by hand!

  6. Iain
    Posted October 28, 2005 at 9:55 pm | Permalink

    Firstly, I’d like to say what a great site this is and the Killers posted here are soooo much better than those in the T2. I really enjoy the extra challenge that the puzzles here usually give (I especially enjoyed the Killer X – any chance of another?).

    It was therefore with great anticipation that I have been waiting all week for the “insane” puzzle to be put up to challenge me for hours. It was so disappointing to have finished it in about 15 mins (well done for getting your programme to do it in that time udosuk), which was probably about half the time it took me to do the easy yesterday!! Can we please have a proper insane one next time:-)

    Keep up the good work djape.

  7. cindy_spain
    Posted October 28, 2005 at 10:29 pm | Permalink

    Yeah, too easy to be rated “insane”. Took me also less than 20 min. I was hoping for a real challenge today 🙁

  8. sum gy
    Posted October 29, 2005 at 12:38 am | Permalink

    I also did not find this one all too difficult (no program involved). I agree with Cathy that last week’s IQ was also more difficult; took me more than 1 day that one.

  9. Myriam
    Posted November 24, 2005 at 4:39 pm | Permalink

    Pleaeaease explain: killer IQ 233300 from archives. How do you solve this if there is no single innie or outie from any multiple-of-9-shape??????

  10. Posted November 24, 2005 at 4:52 pm | Permalink

    Myriam – here is one cell that you can solve very easy:
    R3C1 = 7. Why? Well, the cage with 3 cells and the sum of 24 can only be 7+8+9. Also, in row 3 there is a cage with the sum 17 which can only be 8+9. So, you have a naked subset, meaning that in row 3 numbers 8 and 9 can only be placed in columns 5 and 6 and nowhere else.

    So, the only possible value for R3C1 = 7.

    There are other similar clues that lead to the solution to this very difficult puzzle.

  11. Myriam
    Posted November 24, 2005 at 6:11 pm | Permalink

    Thanks dj, but that much i had figured out. It’s after that where I got stuck. Is it also: the bottom row: 5=2/3 or 1/4 but cannot be 1/4 because in the same row there’s a 6 which has either 1 or 4 in its solution?

  12. Myriam
    Posted November 24, 2005 at 6:12 pm | Permalink

    Oh and, is this a puzzle with no innies/outies but only ‘matches’?

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