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README.md

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+# sudoku
+
+命令行数独。
+
+## Features
+- Random sudoku puzzles with different levels.
+- Undo and redo.
+- Hint.
+- Only support Chinese currently.
+- : )
+
+## Run & Build
+To run the game:
+```
+cd sudoku
+cargo run
+```
+
+To build the game:
+```
+cargo build --release
+```