二叉树

 

二叉树基本操作代码

#include "stdafx.h"

#include "stdlib.h"

#include "string.h"



#define MAX 100

typedef char Elemtype;



typedef struct BTNODE

{

    Elemtype data;

    BTNODE *left;

    BTNODE *right;

} BTNode;



void CreateBTNode(BTNode *&root, char *str)

{

    BTNode *p = NULL;

    BTNode *st[MAX] = {NULL};

    int top = -1;

    int i = 0;

    int k = 0;

    char ch = str[i];



    while ('\0' != ch)

    {

        switch (ch)

        {

        case '(':

            {

                top++;

                st[top] = p;

                k = 1;

                break;

            }

        case ')':

            {

                top--;

                break;

            }

        case ',':

            {

                k = 2;

                break;

            }

        default:

            {

                p = (BTNode*)malloc(sizeof(BTNode));

                if (NULL == p)

                {

                    return;

                }

                p->data = ch;

                p->left = p->right = NULL;



                if (!root)

                {

                    root = p;

                } 

                else

                {

                    switch (k)

                    {

                    case 1:

                        st[top]->left = p;

                        break;

                    case 2:

                        st[top]->right = p;

                        break;

                    }

                }

                break;

            }

        }

        ch = str[++i];

    }

}



void DispBTNode(BTNode *&root)

{

    if (root)

    {

        printf("%c", root->data);

        if (root->left || root->right)

        {

            printf("(");

            DispBTNode(root->left);

            if (root->right)

            {

                printf(",");

                DispBTNode(root->right);

            }

            printf(")");

        }

    }

}



int GetBTNodeDepth(BTNode *&root)

{

    int iLeftDepth  = 0;

    int iRightDepth = 0;



    if (!root)

    {

        return 0;

    }



    iLeftDepth  = GetBTNodeDepth(root->left);

    iRightDepth = GetBTNodeDepth(root->right);

    return (iLeftDepth > iRightDepth ? (iLeftDepth+1):(iRightDepth+1));

}



void PreOrder(BTNode *&root)

{

    if (root)

    {

        printf("%c\t", root->data);

        PreOrder(root->left);

        PreOrder(root->right);

    }

}



void PreOrder1(BTNode *&root)

{

    int top = -1;

    BTNode *p = NULL;

    BTNode *st[MAX] = {NULL};



    if (root)

    {

        top++;

        st[top] = root;



        while (top > -1)

        {

            p = st[top];

            top--;

            printf("%c\t", p->data);

            if (p->right)

            {

                top++;

                st[top] = p->right;

            }

            if (p->left)

            {

                top++;

                st[top] = p->left;

            }

        }

    }

}



void InOrder(BTNode *&root)

{

    if (root)

    {        

        PreOrder(root->left);

        printf("%c\t", root->data);

        PreOrder(root->right);

    }

}



void PostOrder(BTNode *&root)

{

    if (root)

    {        

        PreOrder(root->left);        

        PreOrder(root->right);

        printf("%c\t", root->data);

    }

}



int _tmain(int argc, _TCHAR* argv[])

{

    BTNode *root = NULL;

    char *str = "A(B(D(,G)),C(E,F))";

    CreateBTNode(root, str);

    DispBTNode(root);

    printf("\r\n");

    printf("The BTree's Depth = %d\r\n", GetBTNodeDepth(root));



    printf("PreOrder:\r\n");

    PreOrder(root);

    printf("\r\n");



    printf("InOrder:\r\n");

    InOrder(root);

    printf("\r\n");



    printf("PostOrder:\r\n");

    PostOrder(root);

    printf("\r\n");

    return 0;

}