前序遍历 

struct Node{	Node*left;	Node*right;	int data;	Node(){ func; }};Node* create(Node*p, int depth){	if (p && depth)	{		p->left = new Node;		p->right = new Node;		p->data = depth;		create(p->left, depth - 1);		create(p->right, depth - 1);	}	if (!depth)	{		p->left = nullptr;		p->right = nullptr;		p->data = depth;	}	return p;}void print1(Node*p){	if (p)	{		cout << p->data << " ";		print1(p->left);		print1(p->right);	}}void print2(Node*head)//利用stack 模拟函数调用过程 来遍历{	stack
    
      s;	Node*p = head;	{		while (p)		{			s.push(p);			cout << p->data << " ";			p = p->left;		}		while (!s.empty())		{			Node*pp = s.top();			if (pp->right && pp != head)			{				cout << pp->right->data << " ";			}			s.pop();		}	}	{		p = head->right;		while (p)		{			s.push(p);			cout << p->data << " ";			p = p->left;		}		while (!s.empty())		{			Node*pp = s.top();			if (pp->right				&& pp != head)			{				cout << pp->right->data << " ";			}			s.pop();		}	}}int main(){	Node* head = new Node;	create(head, 2);	head->data = 10;	head->left->data = 6;	head->right->data = 14;	head->left->left->data = 4;	head->left->right->data = 8;	head->right->left->data = 12;	head->right->right->data = 16;	print1(head);//递归遍历	cout << endl;	print2(head);//循环遍历	system("pause");	return 0;}
    

中序

void print2(Node*head){	stack
    
      s;	Node*p = head;	{		while (p)		{			s.push(p);		//	cout << p->data << " ";			p = p->left;		}		while (!s.empty())		{			Node*pp = s.top();			cout << pp->data << " ";			if (pp->right && pp != head  )			{								cout << pp->right->data << " ";			}			s.pop();		}	}	{		p = head->right;		while (p)		{			s.push(p);					p = p->left;		}		while (!s.empty())		{			Node*pp = s.top();			cout << pp->data << " ";			if (pp->right&& pp != head)			{				cout << pp->right->data << " ";			}			s.pop();		}	}}
    

后序

void print2(Node*head){	stack
    
      s;	Node*p = head;	{		while (p)		{			s.push(p);				p = p->left;				}		while (!s.empty())		{			Node*pp = s.top();				if (pp->right && pp != head  )			{								cout << pp->right->data << " ";			}				if ( pp != head)			cout << pp->data << " ";			s.pop();		}	}	{		p = head->right;		while (p)		{			s.push(p);			p = p->left;		}		while (!s.empty())		{			Node*pp = s.top();					if (pp->right&& pp != head)			{				cout << pp->right->data << " ";			}				cout << pp->data << " ";			s.pop();		}	}	cout << head->data << " ";}