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Tough Sudoku for 30/October/2005


Choose a number, and place it in the grid above.

  1 2 3 4 5 6 7 8 9
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Sudoku Solving Techniques

Submitted by: sudoku lover

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10:10 (~3:30 to setup.. the rest to solve).. this one was a bit hard.. a lot of non doubles.. my only advice.. keep looking for spots where the numbers just can not be.. really the only way i was able to solve this one.. good luck.. :)
14 min,much better this time.May be I was lucky with interim assumptions,which in tough games I did not find yet the method not to need them.
Same as yesterday, up to minor changes.
aprpaently it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. Ptiy it's not the smae for nmbuers.
Hi _From The Untied Knigdom.
I had already heard about that stuff of mixing letters, but your conclusion ranks it up around my alltime favorites !(truly speaking lol=mdr= mort de rire in french)
The only possible explanation why no one jumped on that howling typo yesterday.
Short hints, FCs(=forbidding chains), complete proof in sandbox.
Anyone brave enough to work on equivalent puzzles ? Compare yesterday's and today's, they're very close. You can open two windows and solve them in parallel, or read the both proofs in parallel. It's striking.
Common pattern : More...
sorry, I missed the 1 before the 3. 13.56
i think it is much simpler than yesterday.65 straight by eliminations. Then d5=5.Then straight
good night peoples. I am pooped. Need sleep and nice warm bed. mmmm. Sweet dreams if you're heading off to bed.
ZZZZZZZZzzzzzzz.. Damn near fell asleep then !!! and that was just reading a couple of the longer comments....
I have no idea how people get the sub-4 min times. Heck, it takes me 4 minutes just to set up.

Are others doing the same cross-hatch set-up, listing all the possibilities in each square, and then eliminating via a walkthrough?

I wonder if I am not using (as in 'haven't thought of') some very useful methods to speed the process up.

Dear God, someone help me... :-)
Brain too thick to do the tough today, just wanted to say hi to all regs!!
Need advice...check out gd's sandbox...lots of advice and hints. Also, don't worry so much about time, its about the chat! Wait no...don't worry about the time, its all in good fun!! I have been doing this for over a month and it still takes me 10+ minutes to do a 'tough'. Have fun!
sorry Ajay, this one is exactly as simple/difficult as yesterday's, in fact it is the same up to minor changes. See in sandbox, and my comment just above.
10+ minutes? That's supposed to be a bad time? Well I guess it takes me 10+ too: 10+++++++...

Yes, gb I noticed the similarity to yesterday's when I was setting up. So that should have made it easier for me, right? No! If anything, I had more trouble. Maybe I'm still in a morning fog.

Do you have any comments on the time issue gb?
ML in DF. My usual times are around the 14 min mark doing it the way you suggest. I was puzzled by these superquick times so I tried just looking at the puzzle and putting in numbers that felt right. I got a few wrong red flashes ( I didn't allow wrong answers)and lo and behold I get a time of under 4 mins. Perhaps thats how they do it.
Sorry, I meant ML in SF but the characters are next to each other on the keyboard!.
13.01 - have looked at the hints n stuff and find them more complicated than the puzzle - think I'll just be satified with taking ages and enjoying the challenge
39:19; thought this was a little harder than yesterday, still having hard time finding chains takes me several minutes to find.
Strange but I did this in 4.36 never have i done a tough one so fast!!!
14.38 7:21 to setup, the rest to solve
please reread both proofs of yesterday's and today's, the similarity is obvious.

On the time issue : Some stop when they've found ONE solution, others (like me) stop when they've found ALL solutions (generally only one, but it's making sure it's the only one that is time More...
gb: how do you go about finding more than one solution? When you get one right solution it stops timer and clears screen. Do you print it out and solve on paper, while timer is going?
Thanks GB for pointing out mistake.Reworked the proof.51 straight eliminations. then a nishio takes me to 54. another nishio takes me to the final solution.
20.27,and I am obviously in the presence of greatness.GB,do your initials stand for Great Brain?I must admit that I was closer to Grate Brain myself.Always get 'em in the end!Bye.
Took me ages - but got there in the end!
Still cant work out the forbidding chains - I must be really thick today...
A great puzzle! Xwing helped me in this one. Time was about 12 minutes (interruptions; how dare people call me when I'm trying to do my Sudoku?!?)
What a great picture! This took me so long to do, but worth it.
Night all! Off to bed for an extra hour's sleep - our clocks go back tonight
6:28 - forgot to set the timer for the set-up. One way to keep my times low!
25.45 I think I'm improving - but still slow compared to the masters - I bow to your greatness = g'night
For all those in countries putting their clocks back - Tonight is the night you can do it in minus minutes. Start at 1.55, finish at 1.05.
-10mins, absolute bargain :-)))
Reminds me of a rude joke -

Q - Why do women like Santa?

A - He may only come once a year, but when he does he sure fills your stockings.
8.59 yeah, I did it! Have a great Sunday!
Which reminds me of another joke -

A lecturer is giving a lesson regarding the relationship between the frequency of having s_x and happiness.
To demonstrate his point he asks all the students who get it at least once a day to put their hands up?
Lots of grinning people raise their More...
c't'd -
A few very glum looking students raise their hands.
And how about those who only get it once a year, he asks?
And one person up the back, looking extremely happy, waves his hand in the air and jumping up and down in his seat.
The lecturer is a bit put out by this, since it goes against his theory, and asks “if you only get it once a year how come you are so happy?”
c't'd again -
And the person shouts out “Tonight's THE night, tonight's THE night...”
Jimmmy you naughty boy lol :))
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