Solve sudoku game, written in Fortran
Fortran书写的数独求解器
https://www.thelearningpoint.net/computer-science/c-program-sudoku-solver
+------+------+------+
| 0 0 0| 1 0 8| 2 5 0|
| 0 6 0| 0 0 3| 0 1 7|
| 4 1 5| 0 0 0| 0 0 0|
+------+------+------+
| 0 0 8| 4 0 0| 6 0 9|
| 0 2 0| 0 0 0| 1 0 5|
| 6 0 0| 8 1 0| 0 0 0|
+------+------+------+
| 0 0 1| 6 0 0| 9 2 0|
| 0 4 0| 0 5 0| 0 0 8|
| 9 0 0| 0 8 4| 0 7 0|
+------+------+------+
+------+------+------+
| 3 7 9| 1 4 8| 2 5 6|
| 8 6 2| 5 9 3| 4 1 7|
| 4 1 5| 7 2 6| 8 9 3|
+------+------+------+
| 1 5 8| 4 7 2| 6 3 9|
| 7 2 4| 3 6 9| 1 8 5|
| 6 9 3| 8 1 5| 7 4 2|
+------+------+------+
| 5 8 1| 6 3 7| 9 2 4|
| 2 4 7| 9 5 1| 3 6 8|
| 9 3 6| 2 8 4| 5 7 1|
+------+------+------+