#define MAX 25

typedef struct NodeTag {
	int data;
	struct NodeTag *Llink;
	struct NodeTag *Rlink;
} TreeNode;

void check_command_line(int, char *[MAX], char [MAX], char [MAX]);
TreeNode *initialize_tree(void);
void add_node(int, TreeNode *);
void preorder_display(TreeNode *);
void inorder_display(TreeNode *);
void postorder_display(TreeNode *);