Introduction - If you have any usage issues, please Google them yourself
Generate binary input method in accordance with the ordinary binary input, represented by an empty node or @. For example, enter the following tree: A/\ BC/\ DE/\ FG enter the root node: A Enter the two sons of A (@ represents an empty node): BC enter two sons of B (@ represents an empty node): @ Enter the two sons of C @ (@ represents an empty node): two sons DE input of D (@ represents an empty node): two sons FG input E (@ represents an empty node): Enter the two sons of F@@ (@ represents the empty node): Enter the two sons of G@@(@ represents an empty node):