B Set 38 Grid Puzzle

Lights Out: 4x4 Grid #38

Show solution

[{"row":1,"col":0,"label":"B1","description":"Press cell B1 (row 2, column 1)."},{"row":0,"col":2,"label":"A3","description":"Press cell A3 (row 1, column 3)."},{"row":0,"col":3,"label":"A4","description":"Press cell A4 (row 1, column 4)."},{"row":1,"col":3,"label":"B4","description":"Press cell B4 (row 2, column 4)."},{"row":1,"col":2,"label":"B3","description":"Press cell B3 (row 2, column 3)."}]

Title
Lights Out: 4x4 Grid #38
Grid
  • [1,1,1,1]
  • [1,0,1,1]
  • [1,0,1,1]
  • [0,0,0,0]
Solution
  • {"row":1,"col":0,"label":"B1","description":"Press cell B1 (row 2, column 1)."}
  • {"row":0,"col":2,"label":"A3","description":"Press cell A3 (row 1, column 3)."}
  • {"row":0,"col":3,"label":"A4","description":"Press cell A4 (row 1, column 4)."}
  • {"row":1,"col":3,"label":"B4","description":"Press cell B4 (row 2, column 4)."}
  • {"row":1,"col":2,"label":"B3","description":"Press cell B3 (row 2, column 3)."}
SolutionPressCount
5
Question
The grid below shows lights that are ON (●) and OFF (○). Pressing any cell toggles it AND all adjacent cells (up, down, left, right). Find the sequence of presses that turns ALL lights off.
Rules
  • Pressing a cell toggles its state and the state of all orthogonally adjacent cells.
  • Your goal is to turn all lights off.
  • The grid is 4×4. Rows are labeled A–D, columns 1–4.
  • The order of presses does not matter — any order of the correct cells works.
  • Pressing the same cell twice returns it to its original effect (so no cell needs pressing more than once).
Hint
The minimum number of presses is 5. Try working row by row from top to bottom.