#include <iostream>
using namespace std;
typedef char VAL_TYPE; //说明此二叉树用来存放字符数据
typedef struct Node
{
VAL_TYPE data;
Node* parent;
Node* lchild;
Node* rchild;
} Node, *BT;
//创建二叉树
void CreateBT(BT* bt, Node* parent)
{
char c;
cin.get(c);
if(c==' ') *bt=NULL;
else
{
//创建根节点
*bt=new Node;
(*bt)->data=c;
(*bt)->parent=parent;
//分别创建左子树和右子树
CreateBT(&((*bt)->lchild),*bt); CreateBT(&((*bt)->rchild),*bt); } } //销毁二叉树 void DestroyBT(BT bt) { if(bt!=NULL) { DestroyBT(bt->lchild); //销毁左子树 DestroyBT(bt->rchild); //销毁右子树 delete bt; //销毁根节点,注意要放在销毁子树之后进行 } } //先序遍历 void PreOrder(BT bt, int(*visit)(char&)) { if(bt!=NULL) { if(!visit(bt->data)) return; //访问根节点 PreOrder(bt->lchild,visit); //先序遍历左子树 PreOrder(bt->rchild,visit); //先序遍历右子树 } } //中序遍历 void InOrder(BT bt, int(*visit)(char&)) { if(bt!=NULL) { InOrder(bt->lchild,visit); //中序遍历左子树 if(!visit(bt->data)) return; //访问根节点 InOrder(bt->rchild,visit); //中序遍历右子树 } } //后序遍历 void PostOrder(BT bt, int(*visit)(char&)) { if(bt!=NULL) { PostOrder(bt->lchild,visit); //后序遍历左子树 PostOrder(bt->rchild,visit); //后序遍历右子树 if(!visit(bt->data)) return; //访问根节点 } } int show(char& c) { cout<<c<<' '; return 1; } int main() { BT bt; cout<<"请按照先序遍历方式依次输入各个节点的值:"<<endl; CreateBT(&bt,NULL); cout<<"先序遍历序列:"; PreOrder(bt,show); cout<<endl; cout<<"中序遍历序列:"; InOrder(bt,show); cout<<endl; cout<<"后序遍历序列:"; PostOrder(bt,show); cout<<endl; DestroyBT(bt); return 0; }
转载于:https://my.oschina.net/HappyTeemo/blog/1558494