Timer
00:00:00
Start Pause Reset
16 Comments Previous / NextHelp

Tough Sudoku for 22/January/2009

                 
                 
                 
                 
                 
                 
                 
                 
                 

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

  1 2 3 4 5 6 7 8 9
Check out the latest post in the Sudoku Forum

Sudoku Solving Techniques

Submitted by: sudoku lover

Indicate which comments you would like to be able to see

Cute! Cute! Cute!
22/Jan/09 12:07 AM
Hi Mathman From Tigerland - re your question yesterday.
I can think of two reasons for not being required to prove uniqueness when solving.
1. If the rules state that the solution is unique and contains only numbers 1-9 once each in every column, row, box etc. Then you should be able to More...
22/Jan/09 12:35 AM
Cute!
22/Jan/09 12:47 AM
Hi Jimmy from Scotland,

Thanks for your response to my comment. Having to prove uniqueness makes the puzzle more challenging and therefore, for me, more fun. (Perhaps a year from now I will agree with you!) As to the two points you raised, the first suggests a choice of ground rules, and More...
22/Jan/09 12:58 AM
Who is there? Have a good day/night all of us
22/Jan/09 2:21 AM
Waiting for someone special to return? Reminds me of my daughter waiting for her brother to to get home from school (we're talking 25 years ago).
22/Jan/09 4:40 AM
32:25
22/Jan/09 5:41 AM
That was the first time she decided to pull herself up on anything. She was just looking to see the world outside.

Man that seems SO long ago. We had to put those pants away a few months ago because they became high waters. She is now 17 m.o. and racing around everywhere.
22/Jan/09 6:27 AM
1. Note pair 38 at e2/f1. Unique possibilities: e8=1=h2,d9=7=f6,e3=9 (UP27).
2. Locked 2s at ai59;so pair 38 at e25 make e7=4=f4,f5=5=d3,f3=1. (UP 32).
3. When a2=5,a8=6=i1,g1=5. When a2=9,g1=9,a5=2,i5=3. So g1/i1 are never 3; This makes f1=3, and the rest is solved (UP 81).
22/Jan/09 7:32 AM
37:26
22/Jan/09 12:42 PM
I was able to solve this in a without the step 3 when stuff.

start22
d9723
e8124
f4425
e7426
e3927
f6728
f3129
d3530
f5531 More...
22/Jan/09 1:06 PM
16:01 to you all from Beijing.

I was able to solve this using elementary methods alone.
22/Jan/09 4:39 PM
17:49, hi all.
22/Jan/09 7:37 PM
38:29 Better late than never. (long time to solve plus a day late.)
23/Jan/09 10:59 AM
1)Start at 22,=>UP=27
2)XW(2):a5=a9-i9=i5,=>e5cg9<>2.UP=32
3)Loop:(9)h9=(hp19-2)ac9=(2)a5-(2=3)i5 -(3)h46=(3)h9
=>c9<>34,g46<>3.=>np:bc8=34
4)(56=3)i18-(3=2)i5-(2=9)a5-(9=5)a2,=& gt;i2<>5.=>np:i18=56
5)(5=9)a2-(9)g2=(9-3)g1=(3)f1-(3)e2=(3)e5-(3=2)i5-(2=9)a5
=>a2< ;>9.UP=81
23/Jan/09 1:26 PM

SE=7.3
09/Sep/10 9:06 PM
Please Log in to post a comment.

Not a member? Joining is quick and free. As a member you get heaps of benefits.

Join Now Login