TODO: add method command to Solver 


cmd:^Cmark@nb:~/zzz/sudoku1$ java -jar target/sudoku1-1.0.jar 

 *====================================*
 *    Welcome to Taijimark's Sudoku   *
 *====================================*

 cmd:sample
 ans:sample question, as follows
 . . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . . . . 6 .
 . . . . . . . 5 .
 . 9 . 6 4 2 . 3 .
 . 7 . . . . . . .
 . 2 . . . . 4 . .
 . 8 1 . 9 . 6 . .
 . 4 . 5 8 . 9 . .
 cmd:run
 ans:run result, as follows
 . . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . 2 . . 6 .
 . . . . 1 . . 5 .
 . 9 5 6 4 2 . 3 .
 . 7 . 3 5 8 . 9 .
 9 2 3 . 6 . 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
 cmd:possible
 ans:show possible, as follows
 --- Sudoku 9x9 possible --- (start)
 (1)A:{12},{15},{},{18},{},{},{2578},{},{278}
 (2)B:{246},{56},{},{49},{},{59},{},{},{29}
 (3)C:{134},{135},{},{1489},{},{159},{58},{},{89}
 (4)D:{23468},{36},{24},{79},{},{79},{278},{},{24678}
 (5)E:{18},{},{},{},{},{},{178},{},{78}
 (6)F:{1246},{},{24},{},{},{},{12},{},{246}
 (7)G:{},{},{},{17},{},{17},{},{},{}
 (8)H:{},{},{},{},{},{},{},{},{}
 (9)I:{},{},{},{},{},{},{},{},{}
 --- Sudoku 9x9 possible --- (end)  possible count:84
                                       cells count:32

 cmd:A1=1
...debug here,A1=1 is firing...
 cmd:
doing runCommand on class Solver
command A1=2 is successful to update Question's data
TODO: rollback to previous option


mark@nb:~/zzz/sudoku1$ java -jar target/sudoku1-1.0.jar 

 *====================================*
 *    Welcome to Taijimark's Sudoku   *
 *====================================*

 cmd:sample
 ans:sample question, as follows
 . . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . . . . 6 .
 . . . . . . . 5 .
 . 9 . 6 4 2 . 3 .
 . 7 . . . . . . .
 . 2 . . . . 4 . .
 . 8 1 . 9 . 6 . .
 . 4 . 5 8 . 9 . .
 cmd:run
 ans:run result, as follows
 . . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . 2 . . 6 .
 . . . . 1 . . 5 .
 . 9 5 6 4 2 . 3 .
 . 7 . 3 5 8 . 9 .
 9 2 3 . 6 . 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
 cmd:possible
 ans:show possible, as follows
 --- Sudoku 9x9 possible --- (start)
 (1)A:{12},{15},{},{18},{},{},{2578},{},{278}
 (2)B:{246},{56},{},{49},{},{59},{},{},{29}
 (3)C:{134},{135},{},{1489},{},{159},{58},{},{89}
 (4)D:{23468},{36},{24},{79},{},{79},{278},{},{24678}
 (5)E:{18},{},{},{},{},{},{178},{},{78}
 (6)F:{1246},{},{24},{},{},{},{12},{},{246}
 (7)G:{},{},{},{17},{},{17},{},{},{}
 (8)H:{},{},{},{},{},{},{},{},{}
 (9)I:{},{},{},{},{},{},{},{},{}
 --- Sudoku 9x9 possible --- (end)  possible count:84
                                       cells count:32

 cmd:A1=2
...debug here,A1=2 row#1, seq=1, val=2
...we assume question is 
 2 . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . 2 . . 6 .
 . . . . 1 . . 5 .
 . 9 5 6 4 2 . 3 .
 . 7 . 3 5 8 . 9 .
 9 2 3 . 6 . 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
...and get answer 
...still ok, continue 
 2 . 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . 2 . . 6 .
 . . . . 1 . . 5 .
 . 9 5 6 4 2 . 3 .
 . 7 . 3 5 8 . 9 .
 9 2 3 . 6 . 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
 cmd:possible
 ans:show possible, as follows
 --- Sudoku 9x9 possible --- (start)
 (1)A:{},{15},{},{18},{},{},{578},{},{78}
 (2)B:{46},{56},{},{49},{},{59},{},{},{29}
 (3)C:{134},{135},{},{1489},{},{159},{58},{},{89}
 (4)D:{3468},{36},{24},{79},{},{79},{278},{},{24678}
 (5)E:{18},{},{},{},{},{},{178},{},{78}
 (6)F:{146},{},{24},{},{},{},{12},{},{246}
 (7)G:{},{},{},{17},{},{17},{},{},{}
 (8)H:{},{},{},{},{},{},{},{},{}
 (9)I:{},{},{},{},{},{},{},{},{}
 --- Sudoku 9x9 possible --- (end)  possible count:77
                                       cells count:31

 cmd:A2=1
...debug here,A2=1 row#1, seq=2, val=1
...we assume question is 
 2 1 9 . 3 6 . 4 .
 . . 8 . 7 . 3 1 .
 . . 7 . 2 . . 6 .
 . . . . 1 . . 5 .
 . 9 5 6 4 2 . 3 .
 . 7 . 3 5 8 . 9 .
 9 2 3 . 6 . 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
...and get answer 
ans:auto-run result, as follows 
 2 1 9 8 3 6 5 4 7
 4 6 8 9 7 5 3 1 2
 3 5 7 4 2 1 8 6 9
 8 3 4 7 1 9 2 5 6
 1 9 5 6 4 2 7 3 8
 6 7 2 3 5 8 1 9 4
 9 2 3 1 6 7 4 8 5
 5 8 1 2 9 4 6 7 3
 7 4 6 5 8 3 9 2 1
ans:This Sudoku is solved!
 cmd: