Sudoku

简介

the game's popularity really took off in 2005; it can now be found in many newspapers and magazines around the world.

玩法说明

The objective of sudoku is to enter a digit from 1 through 9 in each cell, in such a way that:

Each horizontal row (shown in pink) contains each digit exactly once
Each vertical column (shown in yellow) contains each digit exactly once
Each subgrid or region (shown in green) contains each digit exactly once

This explains the name of the game; in Japanese, sudoku means something like "numbers singly".

Solving a sudoku puzzle does not require knowledge of mathematics; simple logic suffices. (Instead of digits, other symbols can be used, e.g. letters, as long as there are nine different symbols.)

In each sudoku puzzle, several digits have already been entered (the "givens"); these may not be changed.

The puzzler's job is to fill the remainder of the grid with digits –respecting, of course, the three constraints mentioned earlier.