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Thurs 28 Dec (Thursday, 28th December 2006)
PuzzleLover
Kwon-Tom Obsessive
Puzzles: 1033
Best Total: 38m 17s
Posted - 2006.12.28 05:14:31
I got this far with patterns.  Finishing from here was basically trial and error.  Am I missing some patterns or easy lookaheads?  Thanks.

Gadget1903
Kwon-Tom Addict
Puzzles: 325
Best Total: 23m 39s
Posted - 2006.12.28 05:40:31
You can get a little further realizing that a line above the 1 at r2c9 creates a quick inner loop.

After that I guessed the rest.
m2e
Kwon-Tom Obsessive
Puzzles: 607
Best Total: 16m 43s
Posted - 2006.12.28 06:55:00
Muck around with the 1 @ r4c6. That one should carry you to the end of the puzzle i think.
Filthy
Kwon-Tom Obsessive
Puzzles: 1376
Best Total: 17m 21s
Posted - 2006.12.28 07:37:53
You're missing this common pattern:

becomes
m2e
Kwon-Tom Obsessive
Puzzles: 607
Best Total: 16m 43s
Posted - 2006.12.28 07:52:20
I always forget that one
procrastinator
Kwon-Tom Obsessive
Puzzles: 1083
Best Total: 12m 56s
Posted - 2006.12.28 09:26:09
There's simple counting to be done down the bottom, which also gives you another line on the 2 just above.
foilman
Kwon-Tom Admin
Puzzles: 3405
Best Total: 24m 6s
Posted - 2006.12.28 10:22:08
Quote:
Originally Posted by procrastinator
There's simple counting to be done down the bottom, which also gives you another line on the 2 just above.
Yes, I saw that too - the 4th row from the bottom has just one unknown, and 3 lines, so you know the remaining one must be a line too (to keep the number of lines even).
PuzzleLover
Kwon-Tom Obsessive
Puzzles: 1033
Best Total: 38m 17s
Posted - 2006.12.29 04:06:30
I forgot that upper right pattern, thanks.

Quote:
Originally Posted by foilman
Quote:
Originally Posted by procrastinator
There's simple counting to be done down the bottom, which also gives you another line on the 2 just above.
Yes, I saw that too - the 4th row from the bottom has just one unknown, and 3 lines, so you know the remaining one must be a line too (to keep the number of lines even).
I'm not sure which 2 procrastinator is referring to, but I like that row 7 observation!  When you're counting, do you tend to look for regions, cut sets, or both?  A cut set across row 7 makes the line at r7c6.5 clear (once you look at row 7).  I find it harder to count the lines entering the bottom region on this one.

I'm not finding any cut sets or region entries/exits where I can visualize a count on the top.
procrastinator
Kwon-Tom Obsessive
Puzzles: 1083
Best Total: 12m 56s
Posted - 2006.12.29 04:50:42
Quote:
Originally Posted by puzzlelover

I'm not sure which 2 procrastinator is referring to,

The counting argument gives you a line on a 1, there's a 2-with-an-x just above it, and now one of the three possible pairs of lines doesn't work.

Quote:
Originally Posted by puzzlelover

When you're counting, do you tend to look for regions, cut sets, or both?

If I'm understanding you correctly, then any region has a cutset isolating it from the rest of the graph (The set of (potential) edges which join a point in the region to a point outside). If the region you choose is something like "the bottom four rows", then your cutset will be a single row of vertical edges. Those are the easiest cutsets to count, but some regions don't have a neat cutset like that. So I first detect the (near)-isolated region, then look for the easiest cutset to count. If there is a single row of edges then that will be easiest so I look for a cutset of that ilk first.
PuzzleLover
Kwon-Tom Obsessive
Puzzles: 1033
Best Total: 38m 17s
Posted - 2006.12.29 05:06:47
Quote:
Originally Posted by procrastinator
Quote:
Originally Posted by puzzlelover

I'm not sure which 2 procrastinator is referring to,
The counting argument gives you a line on a 1, there's a 2-with-an-x just above it, and now one of the three possible pairs of lines doesn't work.
Now I see it, but only after placing a few moves.  You're a better reader than I am!  Thanks.
Jankonyex
Kwon-Tom Obsessive
Puzzles: 5669
Best Total: 9m 35s
Posted - 2006.12.29 08:18:17
I remember... I made this then finished the puzzle.

Last edited by Jankonyex - 2006.12.29 08:20:11
PuzzleLover
Kwon-Tom Obsessive
Puzzles: 1033
Best Total: 38m 17s
Posted - 2006.12.30 06:15:27
Quote:
Originally Posted by jankonyex
I remember... I made this then finished the puzzle.
Very nice pattern, noting 4 lines must leave the empty square down/left from 2!  I'm impressed by your ability to quickly see patterns like this in real time.  No wonder you're consistently high in the leaders list!

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