Strategy for solving Lights Out puzzle

[BACK]
Strategy for solving Lights Out puzzle
Posted On: August 26, 2023

Lights Out is a grid-based puzzle where each cell has two states: on/off. You can swap the state of any cell, but when you do so, the adjacent cells (horizontally or vertically) are swapped as well. Given initial the grid with random states, the objective is to set all cells to off state.


However, I've never been able to develop a strategy of how to solve (by hand) this type of puzzle. Usually I end up switching cells at random. What kinds of strategy are available for solving this game?


There are many variations of this puzzle, but I'm only interested in the classic one.


This puzzle is available in many grid sizes. It's desirable, but not required, that the proposed strategies work on all grid sizes.


My usual (and flawed) strategy is trying to clear row after row, from the top to the bottom. Unfortunately, I end up unable to clear the last row, and then I just start swapping cells at random, or just ragequit altogether.


There is an open-source and multi-platform implementation called flip as part of Simon Tatham's Portable Puzzle Collection.


Question from user Denilson Sá Maia at stackexchange.


Answer:

The method I'm about to explain technically works for any size grid, but it requires some knowledge that I don't know how to determine from scratch. If you want to do some searching online related to it, the method is generally referred to as "chasing lights" or "chasing the lights".


Start by pushing the buttons on the second row corresponding to the lit cells on the top row, then the buttons on the third row corresponding to the lit cells in the second row, etc. This is exactly what you were already doing, chasing the lights down to the bottom row, which is where the name comes from. .


Now, as you know, the tricky part comes when you've got a grid that's blank except for the bottom row. At this point, the way to finalize it is to push some specific buttons on the first row corresponding to the lit cells on the bottom row, and then chase the lights down from the top again. If you pushed the right first-row buttons, when you complete the second chase, the puzzle will be solved.


As far as I know, you have to just know which buttons to push on the top row to correspond to a specific pattern that was left on the bottom row after the initial chase. If you can figure out a method of determining the right ones to push on the top, you can probably use a very similar method to generalize this to any size grid. I don't know a method for this though, so I'll, uh, leave that as an exercise to the reader.


For the classic 5x5 version of the puzzle, it turns out that there are only 7 possible patterns on the bottom row after the initial chase down, so I'm just going to list the 7 possible patterns and the corresponding first-row buttons to press for each. Buttons are numbered from left to right.


Answer from user Chad Birch at stackexchange.



[BACK]
Strategy for solving Lights Out puzzle
Posted On: August 26, 2023

Lights Out is a grid-based puzzle where each cell has two states: on/off. You can swap the state of any cell, but when you do so, the adjacent cells (horizontally or vertically) are swapped as well. Given initial the grid with random states, the objective is to set all cells to off state.


However, I've never been able to develop a strategy of how to solve (by hand) this type of puzzle. Usually I end up switching cells at random. What kinds of strategy are available for solving this game?


There are many variations of this puzzle, but I'm only interested in the classic one.


This puzzle is available in many grid sizes. It's desirable, but not required, that the proposed strategies work on all grid sizes.


My usual (and flawed) strategy is trying to clear row after row, from the top to the bottom. Unfortunately, I end up unable to clear the last row, and then I just start swapping cells at random, or just ragequit altogether.


There is an open-source and multi-platform implementation called flip as part of Simon Tatham's Portable Puzzle Collection.


Question from user Denilson Sá Maia at stackexchange.


Answer:

The method I'm about to explain technically works for any size grid, but it requires some knowledge that I don't know how to determine from scratch. If you want to do some searching online related to it, the method is generally referred to as "chasing lights" or "chasing the lights".


Start by pushing the buttons on the second row corresponding to the lit cells on the top row, then the buttons on the third row corresponding to the lit cells in the second row, etc. This is exactly what you were already doing, chasing the lights down to the bottom row, which is where the name comes from. .


Now, as you know, the tricky part comes when you've got a grid that's blank except for the bottom row. At this point, the way to finalize it is to push some specific buttons on the first row corresponding to the lit cells on the bottom row, and then chase the lights down from the top again. If you pushed the right first-row buttons, when you complete the second chase, the puzzle will be solved.


As far as I know, you have to just know which buttons to push on the top row to correspond to a specific pattern that was left on the bottom row after the initial chase. If you can figure out a method of determining the right ones to push on the top, you can probably use a very similar method to generalize this to any size grid. I don't know a method for this though, so I'll, uh, leave that as an exercise to the reader.


For the classic 5x5 version of the puzzle, it turns out that there are only 7 possible patterns on the bottom row after the initial chase down, so I'm just going to list the 7 possible patterns and the corresponding first-row buttons to press for each. Buttons are numbered from left to right.


Answer from user Chad Birch at stackexchange.



[BACK]

How to get the Operating Profit Graph for the entire game? How to get the Operating Profit Graph for the entire game?

Posted On: September 6, 2023
The game shows it only for last few years:. Is it possible to get similar graph for the entire game duration? Question from user ZakiMa at stackexchange. Answer: It's not possible. The...[More]


Why does no one use controllers? Why does no one use controllers?

Posted On: May 14, 2024
Seriously, every video I see online is someone playing the game while have to click every time they want to move and they have a huge action bar at the bottom of the screen. Why don’t more people us...[More]


Frequency of the Golden Bowser Train? Frequency of the Golden Bowser Train?

Posted On: January 28, 2023
Does anyone happen to know how often you can go to the Golden Bowser Train? For those that don't yet know, it is a level with nothing but coins, and is a great way to bolster your extra lives.Questio...[More]


Where should I sell exploration data for the most benefit? Where should I sell exploration data for the most benefit?

Posted On: June 15, 2023
I spend a LOT of time outside the bubble. (Both the Solar bubble and Colonia area.) Sometimes, I'll be out for months at a stretch and come back with tens of millions of CR worth of exploration da...[More]


Is Hogwarts Legacy worth getting? Is Hogwarts Legacy worth getting?

Posted On: August 16, 2023
I recently got a Steam gift card and I’ve been wanting this game but I read some of the reviews and some people were saying that the game got stale after a while. What do you think about this? ...[More]


How can I play Quake on OS X 10.7 or above? How can I play Quake on OS X 10.7 or above?

Posted On: February 9, 2023
Is there any option for native playing Quake on OS X 10.7 and above?Question from user LuisEspinoza at gaming.stackexchange.com.Answer:Yes there is actually a way to play Quake but you'll need the CD ...[More]


Does it make a difference to CP if you feed candies before or after evolving? Does it make a difference to CP if you feed candies before or after evolving?

Posted On: November 10, 2019
When activating the evolution for a caught Pokemon, it seems to amplify the Combat Power (CP). Thus it seems most beneficial to evolve your Pokemon with the highest CP, if you have multiple of the sam...[More]


What does the Reset button on an N64 actually do? What does the Reset button on an N64 actually do?

Posted On: August 17, 2023
The question struck me this morning when I saw my old N64; there's a reset button on it. What does it actually do? Can't remember a moment where I did have to push it. Is it simply a button...[More]


Whats the last GTA V Franklin mission? Whats the last GTA V Franklin mission?

Posted On: January 11, 2023
The only character with a number below their name is Franklin, this indicates that there is a mission remaining, but I cannot find it! Any ideas what it might be? Could it be a street race, as I have ...[More]


How to turn off the Hey, look at that Points! notifications from Xbox Game Bar? How to turn off the Hey, look at that Points! notifications from Xbox Game Bar?

Posted On: March 17, 2023
Every once in a while on the PC, mostly when I start playing a game but sometimes if I'm not playing anything, I get a little popup from the Xbox Game Bar that says "Hey, look at that -- Poin...[More]