You cannot submit for this problem because the homework's deadline is due.

Submit board.c and judge.c only here.

Milestone 2

In this milestone, implement the following functions (in board.c)
- probe()
- showNext()

Hint: Try to use the functions implemented in Milestone 1!
Then, implement the following functions (in judge.c)
- isValidMove()
- updateBoard()
- curPlayer()
- judgeEnd()