二叉树的C++实现

 

/*--------BTree.h---------*/

#ifndef _BTREE_H_

#define _BTREE_H_

 

#include <iostream>

using namespace std;

 

//树节点的结构

typedef class bTree

{

public:

 int data;

 bTree *lchild,*rchild;

}bTreeNode,*pbTreeNode;

 

class BTree

{

public:

 pbTreeNode root;

 BTree();

 ~BTree();

 void Create_BTree(int);   //建立二叉树

 void Preorder(pbTreeNode);  //前序遍历

 void Inorder(pbTreeNode);  //中序遍历

 void Postorder(pbTreeNode);  //后序遍历

 

 int count(pbTreeNode);  //计算二叉树结点的个数

 int LeafNum(pbTreeNode); //计算二叉树叶子的个数

 int NodeNum(pbTreeNode); //计算二叉树度数为1时的结点个数

private:

 static int node_num,leaf_num;

};

 

#endif

 

 

/*-------------BTree.cpp------------*/

 

#include "BTree.h"

int BTree::node_num=0;

int BTree::leaf_num=0;

 

BTree::BTree()

{

 root=NULL;

}

BTree::~BTree()

{

 delete root;

}

 

//建立二叉树

void BTree::Create_BTree(int value)

{

 pbTreeNode newNode=new bTreeNode;

 if(NULL==newNode)

 {

  cout<<"Memory allocate failed!\n";

  exit(-1);

 }

 newNode->data=value;

 newNode->rchild=newNode->lchild=NULL;

 if(NULL==root)

 {

  root=newNode;

 }

 

 else

 {

  pbTreeNode current=root,back=NULL;

  while(NULL!=current)

  {

   back=current;

   if((current->data)>value)

    current=current->lchild;

   else

    current=current->rchild;

  }

  if((back->data)>value)

   back->lchild=newNode;

  else

   back->rchild=newNode;

 }

}

 

//计算二叉树结点的个数

int BTree::count(pbTreeNode Pointer)

{

 if(NULL==Pointer)

  return 0;

 else

  return (count(Pointer->lchild)+count(Pointer->rchild)+1);

}

 

//计算二叉树叶子的个数

int BTree::LeafNum(pbTreeNode Pointer)

{

 if(NULL==Pointer)

  return 0;

 else

 {

  if(NULL==Pointer->lchild && NULL==Pointer->rchild)

   return leaf_num++;

  else

  {

   LeafNum(Pointer->lchild);

   LeafNum(Pointer->rchild);

  }

  return leaf_num;

 }

}

 

//计算二叉树度数为1时的结点个数

//结点所拥有的子树的个数称为结点的度

int BTree::NodeNum(pbTreeNode Pointer)

{

 if(NULL==Pointer)

  return 0;

 else

 {

  if(NULL!=Pointer->lchild && NULL!=Pointer->rchild)

  {

   NodeNum(Pointer->lchild);

   NodeNum(Pointer->rchild);

  }

  if(NULL!=Pointer->lchild && NULL==Pointer->rchild)

  {

   node_num++;

   NodeNum(Pointer->lchild);

  }

  if(NULL==Pointer->lchild && NULL!=Pointer->rchild)

  {

   node_num++;

   NodeNum(Pointer->rchild);

  }

 }

 return node_num;

}

 

//前序遍历

void BTree::Preorder(pbTreeNode Pointer)

{

 if(NULL!=Pointer)

 {

  cout<<" ["<<Pointer->data<<"] ";

  Preorder(Pointer->lchild);

  Preorder(Pointer->rchild);

 }

}

 

//中序遍历

void BTree::Inorder(pbTreeNode Pointer)

{

 if(NULL!=Pointer)

 {

  Inorder(Pointer->lchild);

  cout<<" ["<<Pointer->data<<"] ";

  Inorder(Pointer->rchild);

 }

}

 

//后序遍历

void BTree::Postorder(pbTreeNode Pointer)

{

 if(NULL!=Pointer)

 {

  Postorder(Pointer->lchild);

  Postorder(Pointer->rchild);

  cout<<" ["<<Pointer->data<<"] ";

 }

}

 

 

/*************main.cpp*************/

 

#include "BTree.h"

int main()

{

 int arr[]={7,4,1,5,16,8,11,12,15,9,2};

 int len=sizeof(arr)/sizeof(arr[0]);

 BTree btree;

 

 cout<<"原数组元素为：\n";

 for(int i=0;i<len;++i)

 {

  cout<<" "<<arr[i];

  btree.Create_BTree(arr[i]);

 }

 

 cout<<"\n\n";

 cout<<"二叉树节点个数："<<btree.count(btree.root)<<endl;

 cout<<"\n二叉树叶子个数："<<btree.LeafNum(btree.root)<<endl;

 cout<<"\n二叉树度数为1的节点个数："<<btree.NodeNum(btree.root)<<endl;

 

 cout<<"\n先序遍历：\n";

 btree.Preorder(btree.root);

 cout<<"\n\n中序遍历：\n";

 btree.Inorder(btree.root);

 cout<<"\n\n后序遍历：\n";

 btree.Postorder(btree.root);

 

 cout<<"\n\n";

 return 0;

}