Sudoku (terminal ver)

A very simple Sudoku game played in terminal and a practice for me to learn:

• cmake
• code and compile c++ with multi-files
• Dancing Links algorithm

How to generate a Sudoku

The Sudoku is generated by these steps:

1. Fill 11 blocks randomly and validly (10 blocks is also ok). Dancing Links is used to check whether it is valid or not.
2. Use Dancing Links to fill the whole grids.
3. Remove the number in a block randomly and then check whether there is just one sulotion. If not, restore the block and choose another block randomly.
4. Remove a certain number (according to the difficulty) of blocks to get the Sudoku.