二叉树的建立和遍历

可学习的博客：

http://blog.chinaunix.net/uid-28639221-id-4678881.html

http://blog.csdn.net/cqnuztq/article/details/8896953

http://blog.csdn.net/u010187139/article/details/46778661

http://study.hhit.edu.cn/subject/CourseWare_Detail.aspx?TeachCourseWareID=231

实现代码：

#include <stdio.h>
#include <malloc.h>
#include <iostream>
 
//定义节点 
typedef struct BiNode{
        char data;
        struct BiNode *lch;
        struct BiNode *rch;
}BiNode,*BiTree;
 
//先序拓展序列建立二叉树 
void Create(BiTree &T)
{
        T =(BiNode*) malloc (sizeof(BiNode));
        
        scanf(" %c",&T->data);
        if(T->data=='#') T = NULL;
        if(T){
                printf("");
                Create(T->lch);
                Create(T->rch);
        }
}

int TreeDeep(BiTree T)//树的深度
{
    int deep = 0;
    if(T){
        int leftdeep = TreeDeep(T->lch);
        int rightdeep = TreeDeep(T->rch);
        deep = leftdeep>=rightdeep?leftdeep+1:rightdeep+1;
    }
}
 
//先序遍历 (递归)
void Preorder (BiTree T)
{                    
   if (T) {
      printf(" %c",T->data);             // 访问根结点
       
      Preorder(T->lch); // 遍历左子树
      Preorder(T->rch);// 遍历右子树
   }
}
 
//中序遍历 （递归）
void Inorder (BiTree T)
{
     if(T) {
       Inorder(T->lch);
        
       printf(" %c",T->data);
        
       Inorder(T->rch);    
       }
} 
 
//后序遍历 （递归）
void Postorder (BiTree T)
{
     if(T) {
       Postorder(T->lch);
       Postorder(T->rch);
        
       printf(" %c",T->data); 
     }
} 

//求二叉树叶子结点个数

int Leafcount(BiTree T,int &num)
{  
    if(T){
        if(T->lch ==NULL &&T->rch==NULL)
           num++;
        Leafcount(T->lch,num);
        Leafcount(T->rch,num);
    }
    return num;
}
 
int main()
{
    //建树 
    printf("The fuction Create() is called.
");
    BiTree T;
    Create(T);
     
    //三种遍历递归算法 
    printf("
");    
    printf("The fuction Preorder() is called.
");
    Preorder(T);
     
    printf("
");
    printf("The fuction Inorder() is called.
");
    Inorder(T);
     
    printf("
");
    printf("The fuction Postorder() is called.
");
    Postorder(T);
    printf("
"); 
    
    int deepth=TreeDeep(T);
    printf("The fuction TreeDeep() is called.
");
    printf("%d",deepth);
    printf("
"); 
    
    int num=0;
    Leafcount(T,num);
    printf("The fuction Leafcount() is called.
");
    printf("%d",num);
    printf("
");
     
}