Robert's puzzles 2020-10-20

Post puzzles for others to solve here.

Re: Robert's puzzles 2020-10-20

Postby Mauriès Robert » Wed Oct 28, 2020 3:58 pm

Hi Denis,
Can you formulate these questions in French, via private messages. My bad English makes me misunderstand them. Thank you.
Robert
Mauriès Robert
 
Posts: 585
Joined: 07 November 2019
Location: France

Re: Robert's puzzles 2020-10-20

Postby denis_berthier » Wed Oct 28, 2020 4:54 pm

OK, ça y est.
denis_berthier
2010 Supporter
 
Posts: 3967
Joined: 19 June 2007
Location: Paris

Re: Robert's puzzles 2020-10-20

Postby Mauriès Robert » Fri Oct 30, 2020 2:08 pm

Hi Denis,
denis_berthier wrote:Sticking to the "general nature" of your remarks, my general resolution paradigm is "simplest first". What is yours? In particular:
- in your example, why do you fuse 2 chains and not 3?
- how do you decide where to stop the combination of tracks (which level of DFS)?
- how do you know there isn't a "shorter" solution?
- what's your definition of "shorter" for the full resolution path?

1) My principle (or paradigm) is also to do the simplest, and from this point of view, in my opinion, TDP is the simplest for at least three reasons:
- it's based on the basic techniques (TB) that everybody knows.
- it is very easy to implement because it is based on a simple definition (track) and a simple principle (studying the interactions of two conjugated tracks)
- it avoids (for those who want to or can't) memorising a whole bunch of more or less complicated patterns (fishs of all kinds, etc.).
2)The purpose of my example was only to show that one could, without great complication, obtain more results in one go, but I could indeed have gone further for more eliminations. I will have the opportunity to show this in a future puzzle.
3) In principle, I don't set a limit to the length of a track as soon as it gives me a first result in the beginning of its development (let's say less than 10/12 candidates), precisely to try to get more. However, I sometimes go to the maximum when I am looking for the invalidity of a track in order to establish the level of difficulty (TDP level).
4) and 5)
I am not sure I understand the last two questions, but here is the answer I can give.
I make a distinction between a resolution that uses the simple principle of TDP exploiting different pairs of candidates or groups of candidates, and a resolution whose aim is to seek the shortest route to resolution, i.e. as few tracks as possible regardless of their length.
In the first case my approach is of the same type as those using other techniques: successive eliminations or validations quite simply accessible until the solution is reached so that it leaves no room for chance.
In the second case, we can say that it is T&E, but the goal is to establish a maximum level of difficulty which in my opinion classifies the puzzles by category from level 0 (TB only necessary) to level 13 (Easter Monster) and above.

Cordialy
Robert
Mauriès Robert
 
Posts: 585
Joined: 07 November 2019
Location: France

Previous

Return to Puzzles