ref: 6d4b20c413811a9f88e5be97128b7dd6445bff08
dir: /html/dominosa.html/
Dominosa <p> Tile the rectangle with dominoes (1×2 rectangles) so that every possible domino appears exactly once (that is, every possible pair of numbers, including doubles). <p> Click between two adjacent numbers to place or remove a domino. Right-click to place a line between numbers if you think a domino definitely cannot go there. Dominoes light up red if two identical ones appear on the grid.