Timer
00:00:00

# Tough Sudoku for 19/July/2010

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

Welcome to the Sudoku Forums!

Submitted by: Gath

 Indicate which comments you would like to be able to see GeneralJokesOtherSudoku Technique/QuestionRecipes
 1.UP=25 (record for almost hidden pairs in a chain?)2.(1)g6 = HP(14)g13 - (2)g1 = HP(26)ac1 - HP(17)c13 = (1)c45 => b6<>1 UP=523.(5)h3 = a3 - c2 = c7 - (5=3)a8 - b9 = h9 => h79<>5 UP=81. 19/Jul/10 12:22 AM What a gorgeous vantage point, Wendy! 19/Jul/10 12:41 AM I need to study farpointer's step 2 closely. I did the step from UP25 to UP52 in "if..then" language as follows. Goal: Eliminate 2 from g1. If g1=2, then g3=4 and g6=1. This creates a 14 pair in c45. At this point 7 is the sole remaining candidate for both c3 and d3, and we have More... 19/Jul/10 3:37 AM 11:47 to you all from Portland, Oregon. Lovely, Wendy. 19/Jul/10 3:55 AM (1)g6.....HP(14)g13........................(2)g1.........HP(26)ac1(1)c45..................HP(17) c13 represented as a matrix. rows are strong and columns are weak. cf. Steves' blog: each row contains at least one true entry; each column contains (except first) at most one true More... 19/Jul/10 4:25 AM it's like a jigsaw puzzle. you slot 3 or 4 a == b pieces into the matrix aligning weak links between pieces, aiming for gold in the first column. 19/Jul/10 4:32 AM ...of course, it's better start with two pieces that could yield gold in the first place, to avoid wasted effort. 19/Jul/10 4:52 AM loops as matrix:perfect loop => a is truea...b........c...da.......ewrapped loop a -- f => c == b & e == da...b........c...df.......e 19/Jul/10 5:50 AM farpointer: your technique of using groups is so powerful! Very elegant! 19/Jul/10 6:22 AM 31:30 19/Jul/10 7:40 AM Ah, beautiful Denmark, a stone's throw from Albany. A lovely little town that was virtually taken over by the hippies during the 70's & 80's. There are still quite a few around but it's now quite popular as a retirement town with people from the country and Perth retiring there. 19/Jul/10 11:03 AM Oh Anne and here I was thinking the photo was taken overseas. lol 19/Jul/10 3:08 PM A very beautiful piece of coastline!!! Thanks Wendy for the pic, and Anne for the info! 19/Jul/10 3:09 PM SE=7.2 10/Sep/10 11:05 PM