树的一些基本操作(遍历，构造，高度，节点数，销毁)

树的一些基本操作(遍历，构造，高度，节点数，销毁)
c语言代码如下:

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
struct BinaryTree
{
    struct BinaryTree *pLeft,*pRight;
    int p_value;
};
void createTree(struct BinaryTree **pRoot)
{//这里是双重指针，因为*p会变
    struct BinaryTree *root = *pRoot;
    int val = 0 ;
    scanf("%d",&val);
    if (val == -1)
        root = NULL;
    else
    {
        *pRoot = (struct BinaryTree*)malloc(sizeof(struct BinaryTree));
        (*pRoot)->p_value = val;
        createTree(&(*pRoot)->pLeft);
        createTree(&(*pRoot)->pRight);
    }
}
void preOrder(struct BinaryTree *pRoot)
{
    //printf("fffffff\n");
    if (pRoot != NULL)
    {
        printf("%d ",pRoot->p_value);
        preOrder(pRoot->pLeft);
        preOrder(pRoot->pRight);
      //  printf("\n");
    }
}
void inOrder(struct BinaryTree *pRoot)
{
    if (pRoot != NULL)
    {
        inOrder(pRoot->pLeft);
        printf("%d ",pRoot->p_value);
        inOrder(pRoot->pRight);
        //printf("\n");
    }
}
void postOrder(struct BinaryTree *pRoot)
{
    if (pRoot != NULL)
    {
        postOrder(pRoot->pLeft);
        postOrder(pRoot->pRight);
        printf("%d ",pRoot->p_value);
        //printf("\n");
    }
}
int sumofNode(struct BinaryTree *pRoot)
{
    if (pRoot == NULL)
        return 0;
    else
    {
        return sumofNode(pRoot->pLeft)+sumofNode(pRoot->pRight)+1;
    }
}
int heightofTree(struct BinaryTree *pRoot)
{
    if (pRoot == NULL)
    {
        return 0;
    }
    else
    {
        return (heightofTree(pRoot->pLeft)>heightofTree(pRoot->pRight)?heightofTree(pRoot->pLeft):heightofTree(pRoot->pRight))+1;
    }
}
void destroy(struct BinaryTree *pRoot)
{
    if (pRoot)
    {
            destroy(pRoot->pLeft);
            destroy(pRoot->pRight);
            free(pRoot);
            pRoot = NULL;
    }
}

int main()
{
     struct BinaryTree * rootNode = NULL;
    int choiced = 0;
    while(true)//很重要的哦！！！！！！！！！！！！！！
          {
        system("clear"); //清屏
        printf("\n\n\n                              ---主界面---\n\n\n");
        printf("                     1、创建二叉树                2、先序遍历二叉树\n");
        printf("                     3、中序遍历二叉树            4、后序遍历二叉树\n");
        printf("                     5、统计结点总数              6、查看树深度    \n");
        printf("                     7、消毁二叉树                0、退出\n\n");
        printf("             请选择操作：");
        scanf("%d",&choiced);
        if(choiced == 0)
            return 0;
        else if(choiced == 1)
               {
            system("clear");
            printf("请输入每个结点，回车确认，并以-1结束：\n");
            createTree(&rootNode );
                     }
        else if(choiced == 2)
                     {
            system("clear");
            printf("先序遍历二叉树结果：\n");
            preOrder(rootNode);
            printf("\n");
          // system("pause"); //暂停屏幕
                     }
        else if(choiced == 3)
               {
            system("clear");
            printf("中序遍历二叉树结果：\n");
            inOrder(rootNode);
            printf("\n");
        // system("pause");
                      }
        else if(choiced == 4)
                     {
            system("clear");
            printf("后序遍历二叉树结果：\n");
            postOrder(rootNode);
            printf("\n");
           // system("pause");
                      }
        else if(choiced == 5)
                {
            system("clear");
            int count = sumofNode(rootNode);
            printf("二叉树中结点总数为%d",count);
            //system("pause");
                }
        else if(choiced == 6)
                     {
            system("clear");
            int dep = heightofTree(rootNode);
            printf("此二叉树的深度为%d",dep);
        // system("pause");
                     }
        else if(choiced == 7)
                     {
            system("clear");
            printf("二叉树已被消毁！\n");
            destroy(rootNode);
            printf("\n");
      // system("pause");
                    }
        else
                     {
            system("clear");
            printf("\n\n\n\n\n\t错误选择！\n");
                     }

    }
    return 0;
}

编译后操作(centos 5.5)(以下是部分结果)
请输入每个结点，回车确认，并以-1结束：
1 2 -1 -1 3 -1 -1

先序遍历二叉树结果：
1 2 3 
c++代码如下:

#include<iostream>
using namespace std;
template<class T>
struct BinaryTree
{
    T val;
    BinaryTree<T> *left,*right;
};
template<class T>
void createTree(BinaryTree<T> * &pRoot)//先序构造二叉树
{
    BinaryTree<T> *root = pRoot;
    T val;
    cin >> val;
    if (val == -1)
    {
        root = NULL;
    }
    else
    {
        //BinaryTree<T> *pNod
        pRoot = new BinaryTree<T>();
        pRoot->val = val;
        //pNode->left = NULL;
        //pNode->right = NULL;
        createTree(pRoot->left);
        createTree(pRoot->right);
    }

}
template<class T>
void preOrder(BinaryTree<T> *&pRoot)
{
    if (pRoot)
    {
        cout << pRoot->val<< " ";
        preOrder(pRoot->left);
        preOrder(pRoot->right);
    }
}
template<class T>
void inOrder(BinaryTree<T> *&pRoot)
{
    if (pRoot)
    {
        inOrder(pRoot->left);
        cout << pRoot->val<< " ";
        inOrder(pRoot->right);
    }
}
template<class T>
void postOrder(BinaryTree<T> *&pRoot)
{
    if (pRoot)
    {
        postOrder(pRoot->left);
        postOrder(pRoot->right);
        cout << pRoot->val<< " ";
    }
}
//树中节点总数
template<class T>
int countNode(BinaryTree<T> *&pRoot)
{
    if (pRoot == NULL)
        return 0;
    else{
        return 1+countNode(pRoot->left)+countNode(pRoot->right);
    }
}
//树的深度
template<class T>
int depthOfTree(BinaryTree<T> *&pRoot)
{
    if (pRoot == NULL)
        return 0;
    else
    {
        return (depthOfTree(pRoot->left)>depthOfTree(pRoot->right)?depthOfTree(pRoot->left):depthOfTree(pRoot->right))+1;
    }
}
//销毁二叉树
template<class T>
void destroy(BinaryTree<T> *pRoot)
{
    if (pRoot)
    {
        destroy(pRoot->left);
        destroy(pRoot->right);
        delete pRoot;
        pRoot = NULL;
    }
}
int main ()
{
    BinaryTree<int> * rootNode = NULL;
    int choiced = 0;
    while(true)//很重要的哦！！！！！！！！！！！！！！
          {
        system("clear"); //清屏
        cout<<"\n\n\n                              ---主界面---\n\n\n";
        cout<<"                     1、创建二叉树                2、先序遍历二叉树\n";
        cout<<"                     3、中序遍历二叉树            4、后序遍历二叉树\n";
        cout<<"                     5、统计结点总数              6、查看树深度    \n";
        cout<<"                     7、消毁二叉树                0、退出\n\n";
        cout<<"             请选择操作：";
        cin>>choiced;
        if(choiced == 0)
            return 0;
        else if(choiced == 1)
        {
            system("clear");
            cout<<"请输入每个结点，回车确认，并以-1结束：\n";
            createTree(rootNode );
        }
        else if(choiced == 2)
        {
            system("clear");
            cout<<"先序遍历二叉树结果：\n";
            preOrder(rootNode);
            cout<<endl;
          // system("pause"); //暂停屏幕
        }
        else if(choiced == 3)
        {
            system("clear");
            cout<<"中序遍历二叉树结果：\n";
            inOrder(rootNode);
            cout<<endl;
        // system("pause");
        }
        else if(choiced == 4)
        {
            system("clear");
            cout<<"后序遍历二叉树结果：\n";
            postOrder(rootNode);
            cout<<endl;
           // system("pause");
        }
        else if(choiced == 5)
        {
            system("clear");
            int count = countNode(rootNode);
            cout<<"二叉树中结点总数为"<<count<<endl;
            system("pause");
        }
        else if(choiced == 6)
        {
            system("clear");
            int dep = depthOfTree(rootNode);
            cout<<"此二叉树的深度为"<<dep<<endl;
        // system("pause");
        }
        else if(choiced == 7)
        {
            system("clear");
            cout<<"二叉树已被消毁！\n";
            destroy(rootNode);
            cout<<endl;
      // system("pause");
        }
        else
        {
            system("clear");
            cout<<"\n\n\n\n\n\t错误选择！\n";
        }

    }
}