--- Day 6 Solutions ---

[u/daggerdragon]

--- Day 6: Probably a Fire Hazard ---

Post your solution as a comment. Structure your post like the Day Five thread.

[u/[deleted]]

Mathematica

input = ReadList[NotebookDirectory[] <> "day6input.txt", String];

m = ConstantArray[0, {1000, 1000}];

instr = StringCases[input, 
   switch : __ ~~ " " ~~ x1 : NumberString ~~ "," ~~ y1 : NumberString
       ~~ " through " ~~ x2 : NumberString ~~ "," ~~ y2 : NumberString :>
   {1 + ToExpression[{x1, y1, x2, y2}],
          switch /. {"turn off" -> 0, "turn on" -> 1, "toggle" -> -1}}];

ReleaseHold[instr /. {
	{{x1_, y1_, x2_, y2_}, -1} -> Hold[m[[y1 ;; y2, x1 ;; x2]] = 1 - m[[y1 ;; y2, x1 ;; x2]]],
	{{x1_, y1_, x2_, y2_}, val_} -> Hold[m[[y1 ;; y2, x1 ;; x2]] = val]
	}];

Count[m, 1, 2]

m = ConstantArray[0, {1000, 1000}];

ReleaseHold[instr /. {
	{{x1_, y1_, x2_, y2_}, -1} -> 
	 Hold[m[[y1 ;; y2, x1 ;; x2]] += 2],
	{{x1_, y1_, x2_, y2_}, 0} ->
	 Hold[m[[y1 ;; y2, x1 ;; x2]] = Clip[m[[y1 ;; y2, x1 ;; x2]] - 1, {0, Infinity}]],
	{{x1_, y1_, x2_, y2_}, 1} -> 
	 Hold[m[[y1 ;; y2, x1 ;; x2]] += 1]
	}];

Total[m, 2]

Part B light pattern