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Lights Out! (2) (Posted on 2022-10-31) Difficulty: 3 of 5
Imagine there is a 7x7 grid of lights, and only the middle in the grid is on.

The lights are wired such that when you flip the switch for one light (from on to off or off to on) the others next to it (not diagonally) flip as well.

Using this weird wiring of lights, what is the fewest number of switch changes it takes to turn all the lights off, and which lights should you switch?

Note: Assume all the switches work in the manner explained, and there is one switch for each of the lights.

No Solution Yet Submitted by K Sengupta    
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  Subject Author Date
continuing the fun - editedSteven Lord2022-11-18 19:33:47
continuing the funSteven Lord2022-11-18 06:02:45
further extension...Steven Lord2022-11-16 02:58:12
re(2): Cleaned-up code for the extension and an observationCharlie2022-11-14 14:18:01
re: Cleaned-up code for the extension and an observationBrian Smith2022-11-14 12:06:27
Cleaned-up code for the extension and an observationCharlie2022-11-13 11:32:26
Faster Method -- here's 17 and 19Charlie2022-11-11 22:01:34
comment Steven Lord2022-11-11 15:29:47
re(4): extension of the problem -- 13 and 15Charlie2022-11-11 14:02:56
re(3): extension of the problemCharlie2022-11-11 12:41:43
re(2): extension of the problemSteven Lord2022-11-11 10:45:13
re: extension of the problemBrian Smith2022-11-11 10:37:12
extension of the problemSteven Lord2022-11-11 04:34:13
No SubjectK Sengupta2022-11-05 04:51:36
No Subjectboxnovel2022-11-05 03:40:55
Solutioncomputer solutionCharlie2022-10-31 10:31:43
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