同位 Disjoint

同位数独经常被看作是一种全盘限制类数独，但它也同时是一种额外区域数独。标准数独基础上，每个宫相同的位置上，包括了一组1~N的数字（N是盘面的阶数）。例如，所有的左上角（蓝色格）构成一个额外区域，所有的右上角（黄色格）也如此。

Disjoint is often seen as an all-grid limitted variant, but actually it's also a kind of Extra Regions essentially. Classic rules applied, same position of each Box, contains a group of 1~N (in NxN puzzles). For example, all the upper-left corner (blue cells) form an extra region, and also all the lower-right corner (yellow cells) .

练习 Practice

① 四阶的同位数独是否存在？Does 4x4 Disjoint exist?

答案 Answer

① Yes