遍历二叉树——非递归遍历

“test.cpp”

<strong><span style="font-size:18px;">#include<iostream>using namespace std;#include<stack>#include<queue>template<class T>struct BinaryTreeNode{T _data;BinaryTreeNode<T>* _left;BinaryTreeNode<T>* _right;BinaryTreeNode(const T& data = T()):_data(data),_left(NULL),_right(NULL){}};template<class T>class BinaryTree{typedef BinaryTreeNode<T> Node;public:BinaryTree():_root(NULL){}BinaryTree(const T* arr,size_t size,const T& invalid){size_t index = 0;_root = _GreateTree(arr,size,index,invalid);}~BinaryTree(){_Destory(_root);}BinaryTree(const BinaryTree<T>& bt){_root = _Copy(bt._root);}BinaryTree& operator=(const BinaryTree<T>& bt){if(this != &bt){BinaryTree<T> bt2(bt);swap(_root,bt2._root);}return *this;}void PrevOrder(){_PrevOrder(_root);cout<<endl;}void InOrder(){_InOrder(_root);cout<<endl;}void PostOrder(){_PostOrder(_root);cout<<endl;}size_t Size(){size_t count = _Size(_root);return count;}size_t Depth(){size_t depth = _Depth(_root);return depth;}size_t LeafSize(){size_t count = _LeafSize(_root);return count;}void PrevOrderNonR()//stack{stack<Node*> s;Node* cur = _root;while(cur || !s.empty()){while(cur){cout<<cur->_data<<" ";s.push(cur);cur = cur->_left;}Node* top = s.top();s.pop();cur = top->_right;}cout<<endl;}void InOrderNonR()//stack{stack<Node*> s;Node* cur = _root;while(cur || !s.empty()){while(cur){s.push(cur);cur = cur->_left;}Node* top = s.top();cout<<top->_data<<" ";s.pop();cur = top->_right;}cout<<endl;}void PostOrderNonR()//stack{stack<Node*> s;Node* cur = _root;Node* prev = NULL;while(cur || !s.empty()){while(cur){s.push(cur);cur = cur->_left;}Node* top = s.top();if(top->_right == NULL || top->_right == prev){cout<<top->_data<<" ";s.pop();prev = top;}else{cur = top->_right;}}cout<<endl;}void LayerOrderNonR()//queue{queue<Node*> q;Node* cur = _root;if(cur){q.push(cur);}while(!q.empty()){Node* front = q.front();cout<<front->_data<<" ";q.pop();if(front->_left){q.push(front->_left);}if(front->_right){q.push(front->_right);}}cout<<endl;}protected:size_t _LeafSize(Node* root){size_t count = 0;if(root->_left == NULL && root->_right == NULL){count++;return count;}if(root->_left){count += _LeafSize(root->_left);}if(root->_right){count += _LeafSize(root->_right);}return count;}size_t _Depth(Node* root){if(root == NULL){return 0;}size_t leftcount = _Depth(root->_left) + 1;size_t rightcount = _Depth(root->_right) + 1;return leftcount > rightcount ? leftcount : rightcount;}size_t _Size(Node* root){if(root == NULL){return 0;}return 1 + _Size(root->_left) + _Size(root->_right);}Node* _Copy(Node* root){if(root == NULL){return NULL;}//Node* cur = new Node(root);_Copy(root->_left);_Copy(root->_right);return root;}void _Destory(Node* root){if(root == NULL){return;}Node* del = root;_Destory(root->_left);_Destory(root->_right);delete del;}void _PostOrder(Node* root){if(root == NULL){return;}_PostOrder(root->_left);_PostOrder(root->_right);cout<<root->_data<<" ";}void _InOrder(Node* root){if(root == NULL){return;}_InOrder(root->_left);cout<<root->_data<<" ";_InOrder(root->_right);}void _PrevOrder(Node* root){if(root == NULL){return;}cout<<root->_data<<" ";_PrevOrder(root->_left);_PrevOrder(root->_right);}Node* _GreateTree(const T* arr,size_t size,size_t& index,const T& invalid){Node* root = NULL;if((index < size) && (arr[index] != invalid)){root = new Node(arr[index]);root->_left = _GreateTree(arr,size,++index,invalid);root->_right = _GreateTree(arr,size,++index,invalid);}return root;}private:Node* _root;};void test(){int arr[10] = {1,2,3,'#','#',4,'#','#',5,6};int size = sizeof(arr)/sizeof(arr[0]);BinaryTree<int> bt(arr,size,'#');bt.PrevOrder();bt.PrevOrderNonR();bt.InOrder();bt.InOrderNonR();bt.PostOrder();bt.PostOrderNonR();bt.LayerOrderNonR();cout<<"size: "<<bt.Size()<<endl;cout<<"depth: "<<bt.Depth()<<endl;cout<<"leafsize: "<<bt.LeafSize()<<endl;BinaryTree<int> bt2(bt);bt2.PrevOrder();bt2.PrevOrderNonR();BinaryTree<int> bt3;bt3 = bt;bt3.PrevOrder();bt3.PrevOrderNonR();}int main(){test();return 0;}</span></strong>