有没有三维的“数独”游戏？

wikipedia 说已知存在的是 17 ，好像还不知道最小是多少
The inverse problem—the fewest givens that render a solution unique—is unsolved, although the lowest number yet found for the standard variation without a symmetry constraint is 17, a number of which have been found by Japanese puzzle enthusiasts,[17][18] and 18 with the givens in rotationally symmetric cells. Over 47,000 examples of Sudokus with 17 givens resulting in a uniqHue solution are known.
参考网站
http://people.csse.uwa.edu.au/gordon/sudokumin.php