二叉树的建立与遍历

#include<iostream>
using namespace std;

int num[100];
typedef struct node
{
    struct node *left;
    struct node* right;
    char value;
}BiTreeNode, *BiTree;



void creatBiTree(BiTree &T) // 传引用
{
    char c;
    cin >> c;
    if(c == '0')
       {
         T = NULL;
       }
    else
    {
        T = new BiTreeNode;
        T->value = c;
        creatBiTree(T->left);
        creatBiTree(T->right);
    }
}
//前序遍历二叉树并打印出来

void preorder(BiTree T)
{
    if(T)
    {
        cout << T-> value << " ";
        preorder( T -> left);
        preorder( T -> right);
    }
}
//中序遍历二叉树并打印出来

void midorder(BiTree T)
{
    if(T)
    {
        midorder( T-> left);
        cout << T -> value << " ";
        midorder(T -> right);
    }
}
//后续遍历二叉树并打印出来

void postorder(BiTree T)
{
    if(T)
    {
        postorder(T -> left);
        postorder(T -> right);
        cout << T -> value << " ";
    }
}

int main()
{
    BiTree T;
    creatBiTree(T);
    cout << "creat!!!" << endl;
    cout << "preorder :" << endl;
    preorder(T);
    cout << endl;
    cout << "midorder :" << endl;
    midorder(T);
    cout<< endl;
    cout << "postorder: " << endl;
    postorder(T);
    return 0;
}