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Binary Puzzle

binarypuzzle.com

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Re: Binary Puzzle

#11

Post by tedmiston »

tome wrote: post #6

I wonder how one creates puzzles like this (or indeed creates Sudoku puzzles). I can think of a few strategies 1. Lovingly hand craft them. Extremely labour intensive! 2. Generate random grids and repeatedly remove elements. If that leads to a puzzle with more than one solution, backtrack. 3. Add random elements to an empty grid. Eventually the grid will have one or zero solutions. If zero, backtrack. If one, stop. F…

Sudoku puzzles are created both automatically and semi-automically / modified by hand to make them more elegant or enjoyable. I've bought a few sudoku puzzle books that usually discuss it like an art in the preface.

Re: Binary Puzzle

#14

Post by fenomas »

tome wrote: post #6

I wonder how one creates puzzles like this (or indeed creates Sudoku puzzles). I can think of a few strategies 1. Lovingly hand craft them. Extremely labour intensive! 2. Generate random grids and repeatedly remove elements. If that leads to a puzzle with more than one solution, backtrack. 3. Add random elements to an empty grid. Eventually the grid will have one or zero solutions. If zero, backtrack. If one, stop. F…

> Is there some "analytic" property that guarantees uniqueness of solutions without resorting to some black box solver?

Check out Knuth's Algorithm X. It's an elegant way of analyzing constraint-satisfaction sorts of problems (of which both Sudoku and the linked puzzle are examples).

https://en.wikipedia.org/wiki/Knuth%27s_Algorithm_X

edit: at least I think the linked puzzle is a constraint problem that could be modeled this way. But now that I consider it it's not so obvious...

Re: Binary Puzzle

#16

Post by pavel_lishin »

eldavojohn wrote: post #8
EvanKelly wrote: post #2

Oh Hi ( https://play.google.com/store/apps/details?id=com.presto.ohh... ) is an app I have that has these puzzles. Simple rules and can get surprisingly difficult.

What's the difference between your app (that has 100-500 downloads) and this app that has 100,000-500,000 downloads? https://play.google.com/store/apps/details?id=com.q42.ohhi&h...

Even the description is a word-for-word copy of 0h h1.

Re: Binary Puzzle

#17

Post by alangpierce »

If anyone else was confused by the rule "No more than two similar numbers below or next to each other are allowed", I think it means that you aren't allowed to have three in a row of the same number, horizontally or vertically.

Re: Binary Puzzle

#18

Post by GrantSolar »

I feel that the rules should contain some examples. I spent a while battling a puzzle to realise that I had been interpretting "No more than two similar numbers next to or below each other are allowed." as "A box must have no more than 2 neighbours of each number" i.e. Exactly 2 0s and exactly 2 1s in the non-diagonal neighbours.

I think that what's being referred to is runs of numbers, so if you see 0,0,_ you know the last one must be a 1

Re: Binary Puzzle

#19

Post by GrantSolar »

I feel that the rules should contain some examples. I spent a while battling a puzzle to realise that I had been interpretting "No more than two similar numbers next to or below each other are allowed." as "A box must have no more than 2 neighbours of each number" i.e. Exactly 2 0s and exactly 2 1s in the non-diagonal neighbours.

I think that what's being referred to is runs of numbers, so if you see 0,0,_ you know the last one must be a 1

Re: Binary Puzzle

#20

Post by Avshalom »

GrantSolar wrote: post #18

I feel that the rules should contain some examples. I spent a while battling a puzzle to realise that I had been interpretting "No more than two similar numbers next to or below each other are allowed." as "A box must have no more than 2 neighbours of each number" i.e. Exactly 2 0s and exactly 2 1s in the non-diagonal neighbours. I think that what's being referred to is runs of numbers, so if you see 0,0,_ you know t…

I on the other managed to completely not read the part where each row/column is split between 1s and 0s.

Tatham's version helpfully yells at you when you break the rules which is how I realized I was missing an important bit of information.

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