# Quick Moon-or-Sun Puzzles: 2x1-Dominoes and 1x1-Checkerboards

• Draw a line to make a single loop.
• Lines pass through the centers of cells, horizontally, vertically, or turning. The loop never crosses itself, branches off, or goes through the same cell twice.
• A rectangle, bordered by bold lines, is called a "room".
• Color each room blue or yellow.
• The loop must visit each room once, alternating between blue and yellow rooms.
• In a blue room, you must visit all of the moons and none of the suns; in a yellow room, you must visit all of the suns and none of the moons.
• Seeing the misunderstanding and all that, I'd like to ask clearly: passing through a room WITHOUT a sun or moon counts as part of the sequence? (Ex: Can't go moon-moon but can go moon-blank-moon?) – Belhenix Sep 2 '19 at 17:37
• A suggestion for rephrasing the rules to account for empty rooms: "Color each room blue or yellow. Draw a loop visiting each room once, alternating between blue and yellow rooms. In a blue room, you must visit all of the moons and none of the sums; in a yellow room, you must visit all of the suns and none of the moons." – Deusovi Sep 2 '19 at 19:46
• Welp, got to admit that indeed the original rules may confuse the solver when they are given empty room. For @Belhenix , that's correct: can't go moon-moon but moon-blank-moon is okay (if the second room doesn't contain any sun). And Deusovi , I like and agree with the suggestion, will update the rules accordingly. – athin Sep 2 '19 at 22:45