Creation and traversal of binary tree

I wrote a binary tree operation, referring to the other people's writing, found that should be a good study of other people's wording:

Source Text Address:

http://hi.baidu.com/klcstudy/blog/item/5fdf49b5b57d62ce37d3ca18.html/cmtid/203d9f10fe11210c203f2e8e

Paste the Reference code:

  #include <iostream> using namespace std; Definition of binary tree node class template< Class t> struct Btnode {T data; Btnode <T> * lchild,*rchild; Btnode (t nodevalue = t (), btnode<t>* leftnode = null,btnode<t>* Rightnode = NULL):d ata (nodevalue), Lchild (lef tnode), Rchild (Rightnode) {}//can select the default constructor for the parameter}; The establishment of the binary tree template < Class t> void Createbintree (btnode<t> * &root) {btnode<t>* p = root; btnode<t>* K; T NodeValue; cin>>nodevalue; if (nodevalue==-1) {root=null;} else {root=new btnode<t> (); root->data = NodeValue; Createbintree (root->Lch ILD); Createbintree (Root->rchild); }}//************************************************************************************//Two fork Tree of the first order traversal template < Class t> void Preorder (btnode<t> * & P) {if (p) {Cout<<p->data<< ""; Preorder (P->lchild); Preorder (P->rchild); }}//**************************************************************************************//Two fork tree in the middle sequence traversal template <class t> void Inorder (btnode<t> * & P) {if (p) {inorder (p->lchild); cout<<p->data<< "" ; Inorder (P->rchild); }}//**************************************************************************************//Two fork tree after the post-traversal template <class t> void Levelorder (btnode<t> *& p) {if (p) {Levelorder (p->lchild); Levelorder (p->Rchild); c out<<p->data<< "";}} The number of nodes in the statistic binary tree template <class t> int Countnode (btnode<t> * & P) {if (p = = NULL) return 0; return 1+countnode (P->lchild) +countn Ode (P->rchild); }//***********************************************************************************//Find the depth of the binary tree template< Class t> int Depth (BtnodE<t> *& p) {if (p = = NULL) return-1; int h1 = depth (p->lchild); int h2 = depth (p->rchild); if (H1&GT;H2) re Turn (h1+1); return h2+1; }//***********************************************************************************//Two cross-tree destruction operation template< Class t> btnode<t>* Destroy (btnode<t>* p)//Extinction function, used to destroy each node in the binary tree {if (p) {return destroy (P->lchild); ret Urn Destroy (P->rchild); Delete p; }}//********************************************************************************//main function Design int main () {BTNode <int> * RootNode = NULL; int choiced = 0; while (true) {System ("CLS"); cout<< "/n/n/n---main interface---/n/n/n"; cout<< "1, create two-fork-Tree 2, first-order traverse binary tree/n"; cout<< "3, Middle sequence Traversal binary Tree 4, post-order traversal binary tree/n "; cout<< "5, Statistics node total 6, view tree depth/n"; cout<< "7, destroy the binary tree 0, exit/n/n"; cout<< "Please select the operation:"; cin>>choiced; if (choiced = = 0) return 0; else if (choiced = = 1) {System ("CLS"); cout<< "Please enter each node, return confirmation, and end with-1:/n"; Createbintree (RootNode);} else if (choiced = = 2) {System ("CLS "); cout<< "Sequential traversal of Binary tree results:/n"; Preorder (RootNode); cout<<endl; System ("pause"); } else if (choiced = = 3) {System ("CLS"); cout<< "middle order traversal binary tree Result:/n"; inorder (RootNode); cout<<endl; system ("Pause" ); } else if (choiced = = 4) {System ("CLS"); cout<< "post-traverse binary tree results:/n"; Levelorder (RootNode); cout<<endl; System (" Pause "); } else if (choiced = = 5) {System ("CLS"); int count = Countnode (rootNode); cout<< "The total number of nodes in the binary tree is" <<count<<end L System ("pause"); } else if (choiced = = 6) {System ("CLS"); int dep = depth (rootNode); cout<< "depth of this binary tree is" <<dep<<endl; system ( "Pause"); } else if (choiced = = 7) {System ("CLS"); cout<< "Binary tree has been destroyed. /n "; Destroy (RootNode); cout<<endl; System ("pause"); } else {System ("CLS"); cout<< "/n/n/n/n/n/t error selection. /n "; } } }

such as 5
/     /
3 8
/ /     / /
2 4 6 9
/ /   / / / /    / /
1-1-1-1-17-1-1
/ /              / /
-1-1-1-1

Then the sequence entered is: 5321-1-1-14-1-186-17-1-19-1-1

Note: Because the two fork tree to be created must be a full two fork tree, each end node needs to end with-1.