c++树及树与二叉树的转换

此算法中的树结构为“左儿子有兄弟链接结构”

在这样的一个二叉树中，一个节点的左分支是他的大儿子节点，右分支为他的大兄弟节点。

这里讲的树有递归前根，中根，后根遍历，插入节点，插入兄弟节点，查找结点，释放内存这些功能。

重点说一下查找节点这一算法：

pSTreeNode CTree::Search( pSTreeNode pNode, TreeDataType Value )

{

if ( pNode == NULL )

return NULL;

  if ( pNode->data == Value )

return pNode;

  if ( pNode->pFirstChild == NULL && pNode->pNextBrother == NULL )

return NULL;

else

{

if ( pNode->pFirstChild != NULL )                                    //首先判断根节点的左儿子节点是否为空，若不为空，通过引入指针来寻找节点

{

pSTreeNode pNodeTemp = Search( pNode->pFirstChild, Value );

if ( pNodeTemp != NULL )

return pNodeTemp;

else                                                                               

{

return Search( pNode->pNextBrother, Value );

}

}

else                                                                                 //否则在根节点的右兄弟节点中寻找

return Search( pNode->pNextBrother, Value );

}

}

完整代码如下：

#include <iostream>

using namespace std;

typedef struct STreeNode* pSTreeNode;

typedef int TreeDataType;

//定义结构体

struct STreeNode

{

TreeDataType data;

pSTreeNode pFirstChild;

pSTreeNode pNextBrother;

//结构体构造函数

STreeNode( TreeDataType Value )

{

data = Value;

pFirstChild = NULL;

pNextBrother = NULL;

}

};

//定义类

class CTree

{

public:

CTree();

CTree( TreeDataType Value );

~CTree();

public:

void Insert( TreeDataType parentValue, TreeDataType Value ); // parentValue:该点的父亲节点;Value:该点的值

void InsertBrother( pSTreeNode pParentNode, TreeDataType Value );

pSTreeNode Search( pSTreeNode pNode, TreeDataType Value );

void Preorder( pSTreeNode pNode ); // 前序遍历

void Inorder( pSTreeNode pNode ); // 中序遍历

void postorder( pSTreeNode pNode ); // 后序遍历

void FreeMemory( pSTreeNode pNode ); // 释放内存

public:

pSTreeNode pRoot;

};

//构造函数

CTree::CTree()

{

pRoot = NULL;

}

//构造函数

CTree::CTree( TreeDataType Value )

{

pRoot = new STreeNode( Value );

}

//析构函数

CTree::~CTree()

{

if (pRoot == NULL )

return;

FreeMemory( pRoot );

}

//释放内存

void CTree::FreeMemory( pSTreeNode pNode )

{

if ( pNode == NULL )

return;

if ( pNode->pFirstChild != NULL )

FreeMemory( pNode->pFirstChild );

if ( pNode->pNextBrother != NULL )

FreeMemory( pNode->pNextBrother );

delete pNode;

pNode = NULL;

}

//插入节点

void CTree::Insert( TreeDataType parentValue, TreeDataType Value )

{

if ( pRoot == NULL )

return;

pSTreeNode pFindNode = Search( pRoot, parentValue );

if ( pFindNode == NULL )

return;

if ( pFindNode->pFirstChild == NULL )

{

pFindNode->pFirstChild = new STreeNode( Value );

return;

}

else

{

InsertBrother( pFindNode->pFirstChild, Value );

return;

}

}

//插入右兄弟节点

void CTree::InsertBrother( pSTreeNode pBrotherNode, TreeDataType Value )

{

if ( pBrotherNode->pNextBrother != NULL )

InsertBrother( pBrotherNode->pNextBrother, Value );

else

{

pBrotherNode->pNextBrother = new STreeNode( Value );

return;

}

}

//查找函数

pSTreeNode CTree::Search( pSTreeNode pNode, TreeDataType Value )

{

if ( pNode == NULL )

return NULL;

if ( pNode->data == Value )

return pNode;

if ( pNode->pFirstChild == NULL && pNode->pNextBrother == NULL )

return NULL;

else

{

if ( pNode->pFirstChild != NULL )

{

pSTreeNode pNodeTemp = Search( pNode->pFirstChild, Value );

if ( pNodeTemp != NULL )

return pNodeTemp;

else

{

return Search( pNode->pNextBrother, Value );

}

}

else

return Search( pNode->pNextBrother, Value );

}

}

//前序遍历

void CTree::Preorder( pSTreeNode pNode )

{

if (pNode == NULL)

return;

cout << " " << pNode->data << " ";

Preorder( pNode->pFirstChild );

Preorder( pNode->pNextBrother );

}

//中序遍历

void CTree::Inorder( pSTreeNode pNode )

{

if ( pNode == NULL )

return;

Inorder( pNode->pFirstChild );

cout << " " << pNode->data << " ";

Inorder( pNode->pNextBrother );

}

//后序遍历

void CTree::postorder( pSTreeNode pNode )

{

if ( pNode == NULL )

return;

postorder( pNode->pFirstChild );

postorder( pNode->pNextBrother );

cout << " " << pNode->data << " ";

}

//主函数

int main()

{

CTree* pTree = new CTree( 1 );

pTree->Insert( 1, 2 );

pTree->Insert( 1, 3 );

pTree->Insert( 1, 4 );

pTree->Insert( 1, 5 );

pTree->Insert( 1, 6 );

pTree->Insert( 1, 7 );

pTree->Insert( 4, 8 );

pTree->Insert( 5, 9 );

pTree->Insert( 5, 10 );

pTree->Insert( 6, 11 );

pTree->Insert( 6, 12 );

pTree->Insert( 6, 13 );

pTree->Insert( 10, 14 );

pTree->Insert( 10, 15 );

cout << "前序遍历:" << endl;

pTree->Preorder( pTree->pRoot );

cout << endl;

cout << "中序遍历:" << endl;

pTree->Inorder( pTree->pRoot );

cout << endl;

cout << "后序遍历:" << endl;

pTree->postorder( pTree->pRoot );

cout << endl;

delete pTree;

pTree = NULL;

return 0;

}