数据结构--二叉树

/*******************************************************************
Copyright(c) 2016, Harry He
All rights reserved.
Distributed under the BSD license.
(See accompanying file LICENSE.txt at
https://github.com/zhedahht/CodingInterviewChinese2/blob/master/LICENSE.txt)
*******************************************************************/

//==================================================================
// 《剑指Offer——名企面试官精讲典型编程题》代码
// 作者：何海涛
//==================================================================

#pragma once

struct BinaryTreeNode 
{
    int                    m_nValue; 
    BinaryTreeNode*        m_pLeft;  
    BinaryTreeNode*        m_pRight; 
};

__declspec( dllexport ) BinaryTreeNode* CreateBinaryTreeNode(int value);
__declspec( dllexport ) void ConnectTreeNodes(BinaryTreeNode* pParent, BinaryTreeNode* pLeft, BinaryTreeNode* pRight);
__declspec( dllexport ) void PrintTreeNode(const BinaryTreeNode* pNode);
__declspec( dllexport ) void PrintTree(const BinaryTreeNode* pRoot);
__declspec( dllexport ) void DestroyTree(BinaryTreeNode* pRoot);

 

/*******************************************************************
Copyright(c) 2016, Harry He
All rights reserved.
Distributed under the BSD license.
(See accompanying file LICENSE.txt at
https://github.com/zhedahht/CodingInterviewChinese2/blob/master/LICENSE.txt)
*******************************************************************/

//==================================================================
// 《剑指Offer——名企面试官精讲典型编程题》代码
// 作者：何海涛
//==================================================================

#include <cstdio>
#include "BinaryTree.h"

BinaryTreeNode* CreateBinaryTreeNode(int value)
{
    BinaryTreeNode* pNode = new BinaryTreeNode();
    pNode->m_nValue = value;
    pNode->m_pLeft = nullptr;
    pNode->m_pRight = nullptr;

    return pNode;
}

void ConnectTreeNodes(BinaryTreeNode* pParent, BinaryTreeNode* pLeft, BinaryTreeNode* pRight)
{
    if(pParent != nullptr)
    {
        pParent->m_pLeft = pLeft;
        pParent->m_pRight = pRight;
    }
}

void PrintTreeNode(const BinaryTreeNode* pNode)
{
    if(pNode != nullptr)
    {
        printf("value of this node is: %d\n", pNode->m_nValue);

        if(pNode->m_pLeft != nullptr)
            printf("value of its left child is: %d.\n", pNode->m_pLeft->m_nValue);
        else
            printf("left child is nullptr.\n");

        if(pNode->m_pRight != nullptr)
            printf("value of its right child is: %d.\n", pNode->m_pRight->m_nValue);
        else
            printf("right child is nullptr.\n");
    }
    else
    {
        printf("this node is nullptr.\n");
    }

    printf("\n");
}

void PrintTree(const BinaryTreeNode* pRoot)
{
    PrintTreeNode(pRoot);

    if(pRoot != nullptr)
    {
        if(pRoot->m_pLeft != nullptr)
            PrintTree(pRoot->m_pLeft);

        if(pRoot->m_pRight != nullptr)
            PrintTree(pRoot->m_pRight);
    }
}

void DestroyTree(BinaryTreeNode* pRoot)
{
    if(pRoot != nullptr)
    {
        BinaryTreeNode* pLeft = pRoot->m_pLeft;
        BinaryTreeNode* pRight = pRoot->m_pRight;

        delete pRoot;
        pRoot = nullptr;

        DestroyTree(pLeft);
        DestroyTree(pRight);
    }
}