Sanaku Challenging Sample

Post puzzles for others to solve here.

Sanaku Challenging Sample

Sanaku is very similar to Hashiwokakero=> http://cross-plus-a.com/puzzles.htm#Hashiwokakero

The rules are the bit different though:

The goal is to connect all the islands(Circles) by drawing a series of bridges(Lines) between the islands. The bridges must follow certain criteria:
• Bridges must not cross each other.
• They may only run horizontally, vertically, or diagonally (45 degrees)
• At most one bridge connects a pair of islands.
• The number of bridges connected to each island must match the number on that island.
• The bridges must connect the islands into a single connected group.
• Some bridges are given initially, the goal is to find the remaining bridges

Note: Dotted gray lines show possible bridges, it's just to help you solve the puzzle, not a constraint

Here's a sample:

Netwrok9_NotEasy.png (49.64 KiB) Viewed 158 times

Netwrok9_NotEasy.pdf

Posts: 52
Joined: 31 July 2019

Re: Sanaku Challenging Sample

Has anyone solved this? Seems too tough for me I get ten bridges easily and then nothing (but some eliminations). So many candidates left that I can't even envision an effective T&E strategy (nor would feel like implementing it anyway). What am I missing?

SpAce

Posts: 1656
Joined: 22 May 2017

Re: Sanaku Challenging Sample

SpAce wrote:Has anyone solved this? Seems too tough for me I get ten bridges easily and then nothing (but some eliminations). So many candidates left that I can't even envision an effective T&E strategy (nor would feel like implementing it anyway). What am I missing?

Make sure you don't create Islands ( a set of nodes that are disconnected from the rest ) , basically every node must connect to at least one node that has number greater than 1,

Posts: 52
Joined: 31 July 2019

Re: Sanaku Challenging Sample

SpAce wrote:Has anyone solved this? Seems too tough for me I get ten bridges easily and then nothing (but some eliminations). So many candidates left that I can't even envision an effective T&E strategy (nor would feel like implementing it anyway). What am I missing?

Make sure you don't create Islands ( a set of nodes that are disconnected from the rest ) , basically every node must connect to at least one node that has number greater than 1,

Of course, that's basic. I look at deadly patterns like 1-2-2-2-1 (and longer and more complex ones too) to see if avoiding them forces some bridges or at least blocks some connections. Another thing I do is to see if some connections (especially longer ones) would block some islands from having their fill etc (and if so, those connection possibilities can be eliminated). I've used those techniques here as well, but I still can't seem to advance past the first ten (new) bridges. I get some further eliminations, but I still can't see significant openings. Either this is actually difficult, or I'm just blind to something.

SpAce

Posts: 1656
Joined: 22 May 2017

Re: Sanaku Challenging Sample

Do these puzzles have a rating or solving time?

A walk-through example would also be helpful

tarek

tarek

Posts: 3080
Joined: 05 January 2006

Re: Sanaku Challenging Sample

tarek wrote:Do these puzzles have a rating or solving time?

A walk-through example would also be helpful

tarek

Hi Tarek,

I design these puzzle for fun in my spare time which is quire scarce these days, I'll create a walkthrough as soon as I can

Regards,

-Kousha

Posts: 52
Joined: 31 July 2019

Re: Sanaku Challenging Sample

SpAce wrote:
SpAce wrote:Has anyone solved this? Seems too tough for me I get ten bridges easily and then nothing (but some eliminations). So many candidates left that I can't even envision an effective T&E strategy (nor would feel like implementing it anyway). What am I missing?

Make sure you don't create Islands ( a set of nodes that are disconnected from the rest ) , basically every node must connect to at least one node that has number greater than 1,

Of course, that's basic. I look at deadly patterns like 1-2-2-2-1 (and longer and more complex ones too) to see if avoiding them forces some bridges or at least blocks some connections. Another thing I do is to see if some connections (especially longer ones) would block some islands from having their fill etc (and if so, those connection possibilities can be eliminated). I've used those techniques here as well, but I still can't seem to advance past the first ten (new) bridges. I get some further eliminations, but I still can't see significant openings. Either this is actually difficult, or I'm just blind to something.

Sorry SpAce for not being responsive, one hidden fact is that there's no loops, you can conclude that by summing up the number of each island and compare it against the number of islands,

Posts: 52
Joined: 31 July 2019