二叉树的基本操作（C语言实现）
#include<stdio.h>#include<stdlib.h>//二叉树的节点定义typedef struct TreeNode{char ch; //数据域struct TreeNode *lchild; //左孩子struct TreeNode *rchild; //右孩子}BTNode,*PBTNode;//先序构造二叉树void createBTree(PBTNode *root){char ch;ch=getchar();if(ch=='#')*root=NULL;else{*root=(PBTNode)malloc(sizeof(BTNode));(*root)->ch=ch;(*root)->lchild=NULL;(*root)->rchild=NULL;createBTree(&(*root)->lchild); createBTree(&(*root)->rchild);}}//先序遍历二叉树void preOrder(PBTNode root){if(root==NULL)return;printf("%-3c",root->ch);preOrder(root->lchild);preOrder(root->rchild);}//中序遍历二叉树void inOrder(PBTNode root){if(root==NULL)return;preOrder(root->lchild);printf("%-3c",root->ch);preOrder(root->rchild);}//后序遍历二叉树void postOrder(PBTNode root){if(root==NULL)return;preOrder(root->lchild);preOrder(root->rchild);printf("%-3c",root->ch);}//输出叶子结点void displyLeaf(PBTNode root){if(root==NULL)return;if(root->lchild==NULL&&root->rchild==NULL) printf("%-3c",root->ch);else{displyLeaf(root->lchild);displyLeaf(root->rchild);}}//左结点插入void inseartLeftNode(PBTNode root,char ch){PBTNode p,newNode;if(root==NULL)return; p=root->lchild;newNode=(PBTNode)malloc(sizeof(BTNode));newNode->ch=ch;newNode->rchild=NULL;newNode->lchild=p;root->lchild=newNode;}//右结点插入void inseartRightNode(PBTNode root,char ch){PBTNode p,newNode;if(root==NULL)return; p=root->rchild;newNode=(PBTNode)malloc(sizeof(BTNode));newNode->ch=ch;newNode->lchild=NULL;newNode->rchild=p;root->rchild=newNode;}//销毁一颗二叉树void clear(PBTNode* root){ PBTNode pl,pr;if(*root==NULL)return; pl=(*root)->lchild; pr=(*root)->rchild; (*root)->lchild=NULL; (*root)->rchild=NULL; free((*root));*root=NULL; clear(&pl); clear(&pr);}//删除左子树void deleteLeftTree(PBTNode root){if(root==NULL)return; clear(&root->lchild);root->lchild=NULL;}//删除右子树void deleteRightTree(PBTNode root){if(root==NULL)return; clear(&root->rchild);root->rchild=NULL;}//查找结点PBTNode search(PBTNode root,char ch){PBTNode p;if(root==NULL)return NULL;if(root->ch==ch)return root;else{ if((p=search(root->lchild,ch))!=NULL)return p;else returnsearch(root->rchild,ch); }}//求二叉树的高度int BTreeHeight(PBTNode root){int lchildHeight,rchildHeight;if(root==NULL)return 0; lchildHeight=BTreeHeight(root->lchild); rchildHeight=BTreeHeight(root->rchild);return (lchildHeight>rchildHeight)?(1+lchildHeight):(1+rchildHeight);}//求叶子结点的个数int countLeaf(PBTNode root){if(root==NULL)return 0; if(root->lchild==NULL&&root->rchild==NULL)return 1;else{return countLeaf(root->lchild)+countLeaf(root->rchild);}}//求所有结点的个数int countAll(PBTNode root){if(root==NULL)return 0;return countAll(root->lchild)+countAll(root->rchild)+1;}//复制二叉树PBTNode copyBTree(PBTNode root){PBTNode p,lchild,rchild;if(root==NULL)return NULL; lchild=copyBTree(root->lchild);rchild=copyBTree(root->rchild); p=(PBTNode)malloc(sizeof(BTNode));p->ch=root->ch;p->lchild=lchild;p->rchild=rchild;return p;}?