ref: d35e4b88e85d9bb4f677083c0808b02f51620c2f
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.