二叉树基本操作C代码

 #include<stdio.h>
 #include<malloc.h>
 #define LEN sizeof(struct ChainTree)
 struct ChainTree
 {
     int num;
     struct ChainTree *left;
     struct ChainTree *right;
 };
 /*函数功能：进行查找操作。*/
 ChainTree *BinTreeFind(ChainTree *bt,int data)//在二叉树中查找值为data的结点。
 {
     ChainTree *p;
     if(bt==NULL)
         return NULL;
     else
     {
         if(bt->num==data)
         return bt;
         else{
             if(p=BinTreeFind(bt->left,data))
                 return p;
              else if(p=BinTreeFind(bt->right,data))
                  return p;
              else
                  return NULL;
           }
     }
 }
 /*函数功能：先序遍历。*/
 void BinTree_DLR(ChainTree *bt)
 {
     if(bt)
     {
         printf("%d",bt->num);
         if(bt->left)
         {
             BinTree_DLR(bt->left);
         }
         if(bt->right)
         {
             BinTree_DLR(bt->right);
         }
     }
     return;
 }
 /*函数定义：后序遍历。*/
 void BinTree_LRD(ChainTree *bt)
 {
     if(bt)
     {
         BinTree_LRD(bt->left);
         BinTree_LRD(bt->right);
         printf("%d",bt->num);
     }
     return;
 }
 /*函数功能：中序遍历。*/
 void BinTree_LDR(ChainTree *bt)
 {
     if(bt)
     {
         BinTree_LDR(bt->left);
         printf("%d",bt->num);
         BinTree_LDR(bt->right);
     }
     return;
 }
 /*函数功能初始化一个二叉树，建立根节点。*/
 ChainTree *InitRoot()
 {
     ChainTree *node;
     node=(struct ChainTree*)malloc(LEN);
     printf("请输入根节点的值：");
     scanf("%d",&node->num);
     node->left=NULL;
     node->right=NULL;
     return node;
 }  

 /*添加数据到二叉树*/
 int BinTreeAddNode(ChainTree *bt,ChainTree *node,int n)
 {
     if(bt==NULL)
     {
         printf("\n父结点不在，请先设置父结点。");
         return ;
     }
     switch(n)
     {
         case :
             if(bt->left)
             {
                 printf("左子树结点不为空。");
                 return ;
             }
             else
                 bt->left=node;
             break;
         case :
             if(bt->right)
             {
                 printf("右子树结点不为空。");
                 return ;
             }
             else
                 bt->right=node;
             break;
             default:
                 printf("参数错误！\n");
             return ;
     }
     return ;
 }  

 /*函数功能：添加结点到二叉树。*/
 void AddNode(ChainTree *bt)
 {
     int data;
     int select;
     ChainTree *node,*parent;
     node=(struct ChainTree*)malloc(LEN);
     printf("\n输入二叉树结点数据");
     scanf("%d",&node->num);
     node->left=NULL;
     node->right=NULL;
     printf("\n输入父结点数据：");
     scanf("%d",&data);
     parent=BinTreeFind(bt,data);
     if(!parent)
     {
         printf("\n未找到父结点。");
     }
     printf("\n1.添加到左子树\n2.添加到右子树\n");
     do{
         scanf("%d",&select);
         if(select==||select==)
         BinTreeAddNode(parent,node,select);
         }while(select!=&&select!=);
 }  

 /*求二叉树叶子结点个数*/
 void CountLeaf(ChainTree *bt,int &count)
 {
     if(bt)
     {
         if((!bt->left)&&(!bt->right))
             count++;
         CountLeaf(bt->left,count);
         CountLeaf(bt->right,count);
     }
 }  

 /*求二叉树深度*/
 int BinTreeDepth(ChainTree *bt)
 {
     int dep1,dep2;
     if(bt==NULL)
     return ;
     else
     {
         dep1=BinTreeDepth(bt->left);                //左子树深度（递归调用）
         dep2=BinTreeDepth(bt->right);              //右子树深度（递归调用）
         if(dep1>dep2)
             return dep1+;
         else
             return dep2+;
     }
 }  

 int main()
 {
     struct ChainTree *p1,*p2,*head,*p3;
     int select = ;
     int countleaf=;                                        //该变量计算叶子结点个数
     while(select!=){
         printf("\n1.设置二叉树根元素\n2.添加二叉树根节点\n3.先序遍历\n4.中序遍历\n5.后序遍历\n6.输出叶子结点个数\n7.求二叉树深度\n0.退出");
         scanf("%d",&select);
         switch(select)
         {
         case :
             head=InitRoot();
             break;
         case :
             AddNode(head);
             break;
         case :
             BinTree_DLR(head);
             break;
         case :
              BinTree_LDR(head);
              break;
         case :
             BinTree_LRD(head);
             break;
         case :
                countleaf=;                                              //求二叉树叶子结点数
             CountLeaf(head,countleaf);
             printf("\n%d",countleaf);
             break;
         case :
             printf("二叉树深度为:%d\n",BinTreeDepth(head));
              break;
         case :
             select = ;
             break;
         }
     }
 }