"C + +" Second clue binary tree and its traversal __c++

#include <iostream> using namespace std;
Enum Pointtag {LINK, THREAD,};
	struct Bintreethingnode {char _data;
	Bintreethingnode*_left;
	Bintreethingnode*_right;
	Pointtag _lefttag;
	Pointtag _righttag; Bintreethingnode (const char &data): _data (data), _left (null), _right (null), _lefttag (LINK), _righttag (LI

NK) {}};
	
	Class Bintreethreading {public:bintreethreading (const char *str) {_creatbintreethreading (_ROOT,STR);//recursively Create two fork tree}
		void Postthread ()//subsequent clue {bintreethingnode*prev = NULL;
	_postoderthread (_root, prev);
		}//subsequent threaded traversal of void Postsort () {bintreethingnode*cur = _root;
		Bintreethingnode *lastvisited = NULL; while (cur) {//always looking for the leftmost leaf node of the two-fork tree cur as the root node//cur->_left!= lastvisited: When cur is found through its left child, do not repeat cur to find the leftmost leaf node W
			Hile (Cur&&cur->_lefttag!= thread&& cur->_left!= lastvisited) {cur = cur->_left;
			if (cur && cur->_righttag = THREAD)///When Cur has no right child, cur can be accessed {	cout << cur->_data << "";
			lastvisited = cur;
				} if (cur = = _root&&cur->_right = NULL)//When the root node is accessed, the traversal completes {cout << cur->_data << "";
			Return


			} cur = cur->_right; When Cur's right child is visited, cur can be accessed. And you know cur no successor, so start looking for the root node of cur while (cur && cur->_right = = lastvisited) {cout << Cur->_data <
				< "";
				lastvisited = cur; _parent (_root, &cur);
				Find the root node of cur if (cur = = lastvisited) {return;  }//while processing is: When Cur is found through its right child} protected:///recursively create two-fork tree void _creatbintreethreading (Bintreethingnode*&root,
			const char *&AMP;STR {if (*str!= ' # ' &&*str!= ' ") {root = new Bintreethingnode (*STR);
			_creatbintreethreading (Root->_left, ++STR);
			if (*str!= ' ") {_creatbintreethreading (root->_right, ++STR); Find the root node of the current node void _parent (Bintreethingnode *&root,bintreethingnode **child) {Bintreethingnode *tmp = *ch Ild;
		if (*child = = root) {return;
				} if (root) {if (Root->_left = = *child | | root->_right = = *child) {*child = root;
			Return
			} if (Root->_lefttag = LINK) {_parent (root->_left, child);
			} if (tmp = = *child&&root->_righttag = LINK) {_parent (root->_right, child); implementation void _postoderthread (Bintreethingnode*&cur, Bintreethingnode*&prev) {if (cur) {i
			F (Cur->_lefttag = LINK) {_postoderthread (cur->_left, prev);
			} if (Cur->_righttag = LINK) {_postoderthread (cur->_right, prev);
				} if (Cur->_left = = NULL) {Cur->_lefttag = THREAD;
			Cur->_left = prev;
				} if (prev&&prev->_right = = NULL) {Prev->_righttag = THREAD;
			Prev->_right = cur;
		} prev = cur;
}} Private:bintreethingnode*_root;
 };