最基本的二叉树

来源：http://blog.csdn.net/hopeyouknow/article/details/6740616?reload

一个最基本的二叉树~~

头文件BiTree.h

typedef int Item;
typedef struct node
{
    struct node * lchild;
    struct node * rchild;
    Item data;
}BiTNode,*BiTree;

/*构造一棵新的二叉树*/
BiTree InitBiTree(BiTNode *root);

/*生成节点*/
BiTNode *MakeNode(Item item,BiTNode *lchild,BiTNode *rchild);
/*释放节点*/
void FreeNode(BiTNode *pnode);

/*清空一棵二叉树*/
void ClearBiTree(BiTree tree);

/*销毁一棵二叉树*/
void DestroyBiTree(BiTree tree);

/*判定是否为空*/
IsEmpty(BiTree tree);

/*返回树的深度*/
GetDepth(BiTree tree);

/*返回根*/
BiTree GetRoot(BiTree tree);

/*返回节点值*/
Item GetItem(BiTNode *pnode);

/*设置节点值*/
void SetItem(BiTNode *pnode,Item item);

/*设置左子树*/
BiTree SetLChild(BiTree parent,BiTree lchild);

/*设置右子树*/
BiTree SetRChild(BiTree parent,BiTree rchild);

/*返回左子树*/
BiTree GetLChild(BiTree tree);

/*返回右子树*/
BiTree GetRChild(BiTree tree);

/*插入新子树*/
BiTree InsertChild(BiTree parent,int lr,BiTree child);

/*删除子树*/
void DeleteChild(BiTree parent,int lr);

/*先序遍历二叉树*/
PreOrderTraverse(BiTree tree,void(*visit)());

/*中序遍历二叉树*/
InOrderTraverse(BiTree tree,void(*visit)());

/*后序遍历二叉树*/
PostOrderTraverse(BiTree tree,void(*visit)());

实现文件BiTree.c如下

#include"BiTree.h"
#include<malloc.h>
#include<stdlib.h>

/*构造一棵新的二叉树*/
BiTree InitBiTree(BiTNode *root)
{
    BiTree tree = root;
    return tree;
}

/*生成节点*/
BiTNode *MakeNode(Item item,BiTNode *lchild,BiTNode *rchild)
{
    BiTNode * pnode = (BiTNode *)malloc(sizeof(BiTNode));
    if(pnode)
    {
        pnode->data = item;
        pnode->lchild = lchild;
        pnode->rchild = rchild;
    }
    return pnode;
}

/*释放节点*/
void FreeNode(BiTNode *pnode)
{
    if(pnode!=NULL)
        free(pnode);
}

/*清空一棵二叉树*/
void ClearBiTree(BiTree tree)
{
    BiTNode * pnode = tree;
    if(pnode->lchild!=NULL)
        ClearBiTree(pnode->lchild);

    if(pnode->rchild!=NULL)
        ClearBiTree(pnode->rchild);

    FreeNode(pnode);
}

/*销毁一棵二叉树*/
void DestroyBiTree(BiTree tree)
{
    if(tree)
        ClearBiTree(tree);
}

/*判定是否为空*/
IsEmpty(BiTree tree)
{
    if(tree==NULL)
        return 0;
    else
        return 1;
}

/*返回树的深度*/
int GetDepth(BiTree tree)
{
    int cd,ld,rd;
    cd = ld = rd = 0;
    if(tree)
    {
        ld = GetDepth(tree->lchild);
        rd = GetDepth(tree->rchild);
        cd = (ld > rd ? ld : rd);
        return cd+1;
    }
    else
        return 0;
}

/*返回根*/
BiTree GetRoot(BiTree tree)
{
    return tree;
}

/*返回节点值*/
Item GetItem(BiTNode *pnode)
{
    return pnode->data;
}

/*设置节点值*/
void SetItem(BiTNode *pnode,Item item)
{
    pnode->data = item;
}

/*设置左子树*/
BiTree SetLChild(BiTree parent,BiTree lchild)
{
    parent->lchild = lchild;
    return lchild;
}

/*设置右子树*/
BiTree SetRChild(BiTree parent,BiTree rchild)
{
    parent->rchild = rchild;
    return rchild;
}

/*返回左子树*/
BiTree GetLChild(BiTree tree)
{
    if(tree)
        return tree->lchild;
    return NULL;
}

/*返回右子树*/
BiTree GetRChild(BiTree tree)
{
    if(tree)
        return tree->rchild;
    return NULL;
}

/*插入新子树*/
BiTree InsertChild(BiTree parent,int lr,BiTree child)
{
    if(parent)
    {
        if( lr == 0 && parent->lchild == NULL)
        {
            parent->lchild = child;
            return child;
        }
        if( lr == 1 && parent->rchild == NULL)
        {
            parent->rchild = child;
            return child;
        }
    }
    return NULL;
}

/*删除子树*/
void DeleteChild(BiTree parent,int lr)
{
    if(parent)
    {
        if( lr == 0 && parent->lchild != NULL)
        {
            parent->lchild = NULL;
            FreeNode(parent->lchild);
        }
        if( lr == 1 && parent->rchild != NULL)
        {
            parent->rchild = NULL;
            FreeNode(parent->rchild);
        }
    }
}

/*先序遍历二叉树*/
PreOrderTraverse(BiTree tree,void(*visit)())
{
    BiTNode * pnode = tree;
    if(pnode)
    {
        visit(pnode->data);
        PreOrderTraverse(pnode->lchild,visit);
        PreOrderTraverse(pnode->rchild,visit);
    }
}

/*中序遍历二叉树*/
InOrderTraverse(BiTree tree,void(*visit)())
{
    BiTNode * pnode = tree;
    if(pnode)
    {
        InOrderTraverse(pnode->lchild,visit);
        visit(pnode->data);
        InOrderTraverse(pnode->rchild,visit);
    }
}

/*后序遍历二叉树*/
PostOrderTraverse(BiTree tree,void(*visit)())
{
    BiTNode * pnode = tree;
    if(pnode)
    {
        PostOrderTraverse(pnode->lchild,visit);
        PostOrderTraverse(pnode->rchild,visit);
        visit(pnode->data);
    }
}

简单测试程序如下

#include"BiTree.h"
#include<stdio.h>
void print(Item item)
{
    printf("%d ",item);
}
main()
{
    BiTNode * n1 = MakeNode(10,NULL,NULL);
    BiTNode * n2 = MakeNode(20,NULL,NULL);
    BiTNode * n3 = MakeNode(30,n1,n2);
    BiTNode * n4 = MakeNode(40,NULL,NULL);
    BiTNode * n5 = MakeNode(50,NULL,NULL);
    BiTNode * n6 = MakeNode(60,n4,n5);
    BiTNode * n7 = MakeNode(70,NULL,NULL);

    BiTree tree = InitBiTree(n7);
    SetLChild(tree,n3);
    SetRChild(tree,n6);

    printf("树的深度为：%d",GetDepth(tree));

    printf("
先序遍历如下：");
    PreOrderTraverse(tree,print);

    printf("
中序遍历如下：");
    InOrderTraverse(tree,print);

    printf("
后序遍历如下：");
    PostOrderTraverse(tree,print);

    DeleteChild(tree,1);
    printf("
后序遍历如下：");
    PostOrderTraverse(tree,print);

    DestroyBiTree(tree);
    if(IsEmpty(tree))
     printf("
二叉树为空，销毁完毕
");
}