基于visual Studio2013解决算法导论之026二叉树



题目

二叉树实现

解决代码及点评

#include<stdio.h>
#include <malloc.h>
#include <stdlib.h>

typedef struct BiTNode
{
	int nValue;
	struct BiTNode *pLChild;
	struct BiTNode *pRChild;
}BiTNode, *PBiTree;

//输入为0表示结点为空
PBiTree Create()
{
	int nValue;
	PBiTree pRoot;
	scanf("%d", &nValue);
	if (nValue == 0)
	{
		pRoot = NULL;
	}
	else
	{
		pRoot = (PBiTree)malloc(sizeof(BiTNode));
		if (NULL == pRoot)
		{
			printf("分配内存失败!\n");
		}
		else
		{
			pRoot->nValue = nValue;
			printf("请输入%d结点的左子结点:", pRoot->nValue);
			pRoot->pLChild = Create();

			printf("请输入%d结点的右子结点:", pRoot->nValue);
			pRoot->pRChild = Create();
		}
	}
	return pRoot;
}

PBiTree Init()
{
	int nValue;
	PBiTree pRoot;
	scanf("%d", &nValue);
	//输入0表示空结点
	if (nValue == 0)
	{
		pRoot = NULL;
		return pRoot;
	}
	else
	{
		pRoot = (PBiTree)malloc(sizeof(BiTNode));
		printf("请输入%d结点的左孩子:");
		pRoot->pLChild = Init();

		printf("请输入%d结点的右孩子:");
		pRoot->pRChild = Init();

		return pRoot;
	}
}
void Visit(PBiTree p)
{
	printf("%d ", p->nValue);
}

void PreOrder(PBiTree pRoot)
{
	if (NULL == pRoot)
	{
		return;
	}
	Visit(pRoot);
	PreOrder(pRoot->pLChild);
	PreOrder(pRoot->pRChild);
}

void PreOrder1(PBiTree pRoot)
{
	PBiTree pStack[100];
	int nTop = 0;
	PBiTree pCur = pRoot;

	while (nTop > 0 || pCur != NULL)
	{
		while (pCur != NULL)
		{//访问结点pCur所有的左孩子 
			Visit(pCur);
			pStack[nTop++] = pCur;
			pCur = pCur->pLChild;
		}

		if (nTop > 0)
		{//出栈 访问右孩子
			nTop--;
			pCur = pStack[nTop];
			pCur = pCur->pRChild;
		}
	}
}

void InOrder(PBiTree pRoot)
{
	if (NULL == pRoot)
	{
		return;
	}
	InOrder(pRoot->pLChild);
	Visit(pRoot);
	InOrder(pRoot->pRChild);
}

void InOrder1(PBiTree pRoot)
{
	PBiTree pStack[100];
	int nTop = 0;
	PBiTree pCur = pRoot;

	while (nTop > 0 || pCur != NULL)
	{
		while (pCur != NULL)
		{
			pStack[nTop++] = pCur;
			pCur = pCur->pLChild;
		}

		if (nTop > 0)
		{
			nTop--;
			pCur = pStack[nTop];
			Visit(pCur);
			pCur = pCur->pRChild;
		}
	}
}

void PostOrder(PBiTree pRoot)
{
	if (NULL == pRoot)
	{
		return;
	}
	PostOrder(pRoot->pLChild);
	PostOrder(pRoot->pRChild);
	Visit(pRoot);
}

void PostOrder1(PBiTree pRoot)
{
	PBiTree pStack[100];
	int nTop = 0;
	PBiTree pCur = pRoot;
	PBiTree IsVisited = NULL;
	while (nTop > 0 || pCur != NULL)
	{
		while (pCur != NULL)
		{
			pStack[nTop++] = pCur;
			pCur = pCur->pLChild;
		}
		pCur = pStack[nTop - 1];
		if (pCur->pRChild == NULL && IsVisited == pCur->pRChild)
		{
			Visit(pCur);
			nTop--;
			IsVisited = pCur;
			pCur = NULL;
		}
		else
		{
			pCur = pCur->pRChild;
		}

	}
}

//逐层遍历二叉树
void LevelOrder(PBiTree pRoot)
{
	if (NULL == pRoot)
	{
		return;
	}
	PBiTree Queue[100];
	int nHead = 0;
	int nTail = 0;
	PBiTree pCur;

	Queue[nTail++] = pRoot;
	while (nHead != nTail)
	{
		pCur = Queue[nHead++];
		Visit(pCur);
		if (pCur->pLChild)
		{
			Queue[nTail++] = pCur->pLChild;
		}
		if (pCur->pRChild)
		{
			Queue[nTail++] = pCur->pRChild;
		}
	}
}

//只有根结点时 高度为1 深度为0
int TreeHight(PBiTree pRoot)
{
	int nCount;
	int nLChild, nRChild;
	if (NULL == pRoot)
	{
		return 0;
	}
	nLChild = TreeHight(pRoot->pLChild);
	nRChild = TreeHight(pRoot->pRChild);
	nCount = nLChild > nRChild ? nLChild : nRChild;

	return nCount + 1;
}

//叶子结点个数
int TreeLeaf(PBiTree pRoot)
{
	int nLChild, nRChild;
	if (pRoot == NULL)
	{
		return 0;
	}
	if (pRoot->pLChild == NULL && pRoot->pRChild == NULL)
	{
		return 1;
	}
	nLChild = TreeLeaf(pRoot->pLChild);
	nRChild = TreeLeaf(pRoot->pRChild);
	return nLChild + nRChild; 
}

int FindParent(PBiTree pRoot, int nValue)
{
	if (pRoot == NULL)
	{
		return 0;
	}
	if (pRoot->pLChild && pRoot->pLChild->nValue == nValue)
	{
		return pRoot->nValue;
	}
	if (pRoot->pRChild && pRoot->pRChild->nValue == nValue)
	{
		return pRoot->nValue;
	}
	FindParent(pRoot->pLChild, nValue);
	FindParent(pRoot->pRChild, nValue);
}

int LeftSibling(PBiTree pRoot, int nValue)
{
	if (pRoot == NULL)
	{
		return 0;
	}

	if (pRoot->pRChild && pRoot->pRChild->nValue == nValue)
	{
		if (pRoot->pLChild)
		{
			return pRoot->pLChild->nValue;
		}
	}
	FindParent(pRoot->pLChild, nValue);
	FindParent(pRoot->pRChild, nValue);
}

int RightSibling(PBiTree pRoot, int nValue)
{
	if (pRoot == NULL)
	{
		return 0;
	}

	if (pRoot->pLChild && pRoot->pLChild->nValue == nValue)
	{
		if (pRoot->pRChild)
		{
			return pRoot->pRChild->nValue;
		}
	}
	FindParent(pRoot->pLChild, nValue);
	FindParent(pRoot->pRChild, nValue);
}

int main()
{
	printf("请输入根结点的值:");
	PBiTree pRoot = Create();

	printf("前序遍历:");
	PreOrder1(pRoot);

	printf("中序遍历:");
	InOrder1(pRoot);

	printf("后序遍历:");
	PostOrder(pRoot);

	printf("逐层遍历:");
	LevelOrder(pRoot);

	printf("二叉树的高度为:%d\n", TreeHight(pRoot));
	printf("二叉树的叶子个数为:%d\n", TreeLeaf(pRoot));

	int rv = FindParent(pRoot, 4);
	if (rv != 0)
	{
		printf("父结点的值为:%d\n", rv);
	}
	else
	{
		printf("该结点无父结点!\n", rv);
	}

	rv = LeftSibling(pRoot, 4);
	if (rv != 0)
	{
		printf("左兄弟结点的值为:%d\n", rv);
	}
	else
	{
		printf("该结点无左兄弟结点!\n", rv);
	}

	system("pause");
	return 0;
}

代码下载及其运行

代码下载地址：http://download.csdn.net/detail/yincheng01/6858815

解压密码：c.itcast.cn

下载代码并解压后，用VC2013打开interview.sln，并设置对应的启动项目后，点击运行即可，具体步骤如下：

1）设置启动项目：右键点击解决方案，在弹出菜单中选择“设置启动项目”

2）在下拉框中选择相应项目，项目名和博客编号一致

3）点击“本地Windows调试器”运行

程序运行结果