二叉树的建立

#include<stdio.h>#include<stdlib.h>typedef struct tree       //定义二叉树的结构{char data;struct tree *lchild;struct tree *rchild;}BinTree;/***创建二叉树*/void CreateTree(BinTree *&pBtree){char c;scanf("%c",&c);if(c=='@')        //子树的结束标识符{pBtree=NULL;}else{pBtree=(BinTree *)malloc(sizeof(BinTree));if(pBtree==NULL){printf("malloc使用失败!\n");exit(0);}pBtree->data=c;CreateTree(pBtree->lchild);   //继续递归去建立左右二叉子树CreateTree(pBtree->rchild);}}/***先序遍历二叉树*/void FirstTraverse(BinTree *&pBtree){if(pBtree==NULL)return;printf("%c",pBtree->data);FirstTraverse(pBtree->lchild);FirstTraverse(pBtree->rchild);}/***求节点的总数*/int sumNode(BinTree *&pBtree){int sum=0;if(pBtree==NULL)return 0; sum++; sum+=sumNode(pBtree->lchild); sum+=sumNode(pBtree->rchild); return sum;}/***销毁二叉树*/void DestroyTree(BinTree *&pBtree){if(pBtree==NULL)return;DestroyTree(pBtree->lchild);DestroyTree(pBtree->rchild);free(pBtree);}int main(){BinTree *pBtree;printf("请输入二叉树的节点:\n");CreateTree(pBtree);printf("二叉树的先序遍历:\n");FirstTraverse(pBtree);printf("\n节点总数是:\n");printf("%d\n",sumNode(pBtree));DestroyTree(pBtree);return 0;}