Questions tagged [lights-out]
A type of puzzle typically involving a grid of lights, in which the challenge is to get them all to the same state (on or off). The trick is that each light also affects a number of its neighbors, with sides and corners affecting fewer.
7
questions
18
votes
5
answers
1k
views
Board with all 2020s
Zeroes are written in all cells of a $5 \times 5$ board. We can take an arbitrary cell and increase by 1 the number in this cell and all cells having a common side with it. Is it possible to obtain ...
- 880
11
votes
2
answers
863
views
Turn on all squares
Take a square grid of size $a\times b$, with all squares being off. You can tap a square, to reverse the state of that square and all squares located in the same column and row as the tapped square. ...
- 2,868
9
votes
1
answer
308
views
Putting up the lights
Feeling festive, you decide it's time to put up the lights. You dig out the box and plug a strand in. Uh oh, they are all the same color. This won't work, these are supposed to be multiple colors ...
- 6,639
7
votes
6
answers
1k
views
Counter Flipping
A counter flip game is played in the following way:
In each move, you can flip an entire row or column
Flipping a row or column inverts all the counters on that row or column from $X$ to $O$ or vice ...
- 170
6
votes
2
answers
476
views
Different numbers in all cells of a 3x3 board
This puzzle is inspired by this one: Board with all 2020s
Zeroes are written in all cells of a 3×3 board. Pressing a cell increases by 1 the number in this cell and all cells having a common side with ...
- 33.1k
6
votes
4
answers
446
views
How to get the least number of flips to a plastic chips to get a certain figure?
The puzzle is as follows:
(Transcription with grammar errors fixed)
A game consists of the following:
The challenge is to flip the chips in such a way so that they are as in state 2. You start in ...
- 1,545
5
votes
2
answers
349
views
Putting up the lights two
I hope you are familiar with this.
Basically
Each strand of 20 lights is wired like a 5x4 grid, and each bulb can be either blue, red, purple, or green. However, when you change the color of 1 ...
- 9,243