#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include<stack>
#include<queue>
using namespace std;
struct BiTreeNode {char data;struct BiTreeNode *left_child;struct BiTreeNode *right_child;
};int N  = 0;void CreateBiTree(BiTreeNode* &T,char array[]){ //按先序输入二叉树中结点的值（一个字符），空格字符代表空树， //构造二叉树表表示二叉树T。 char ch = array[N];N = N + 1; if(ch =='*') T=NULL;//其中getchar（）为逐个读入标准库函数 else{ T=new BiTreeNode;//产生新的子树 T->data=ch;//由getchar（）逐个读入来 CreateBiTree(T->left_child,array);//递归创建左子树 CreateBiTree(T->right_child,array);//递归创建右子树
 }
}//CreateTree void create_T(BiTreeNode* &T, char array[]) {char ch = array[N];N=N+1;if (ch == '*') {T = NULL;} else {T = new BiTreeNode;T->data = ch;create_T(T->left_child, array);create_T(T->right_child, array);}
}// 递归 先序遍历
void pre_order_traverse(BiTreeNode* &T) {// 先序遍历if (T) {cout << T->data << " ";pre_order_traverse(T->left_child);pre_order_traverse(T->right_child);}
}//先序遍历 非递归；
void pre_order_traverse_no_recurse(BiTreeNode* &T) {// 非递归先序遍历二叉树stack<BiTreeNode*> s;BiTreeNode *p = T;// 当栈非空或者p指针非空时调用循环while (p != nullptr || !s.empty()) {while ( p != nullptr) {cout << p->data << " ";s.push(p);p = p->left_child;}if (!s.empty()) {p = s.top();s.pop();p = p->right_child;}}
}// 递归 中序遍历
void in_order_traverse(BiTreeNode* &T) {// 中序遍历if (T) {in_order_traverse(T->left_child);cout << T->data << " ";in_order_traverse(T->right_child);}
}// 中序遍历 非递归
void in_order_traverse_no_recurse(BiTreeNode* &T) {stack<BiTreeNode*> s;BiTreeNode *p = T;while (p != nullptr || !s.empty()) {while ( p != nullptr) {s.push(p);p = p->left_child;}if (!s.empty()) {p = s.top();cout << p->data << " ";s.pop();p = p->right_child;}}
}// 递归 后序遍历
void pos_order_traverse(BiTreeNode* &T) {// 中序遍历if (T) {pos_order_traverse(T->left_child);pos_order_traverse(T->right_child);cout << T->data << " ";}
}// 后序遍历 非递归
void pos_order_traverse_no_recurse(BiTreeNode* &T) {stack<BiTreeNode*> s;BiTreeNode *p = T;BiTreeNode*pp = NULL;while (p != nullptr || !s.empty()) {while ( p != nullptr) {s.push(p);p = p->left_child;}if (!s.empty()) {p = s.top();if(p->right_child==NULL || p->right_child == pp){cout<<p->data<<" ";s.pop();pp = p;p = NULL;}else{p=p->right_child;}}}
}void BFS(BiTreeNode* &T)
{queue<BiTreeNode*>s;BiTreeNode *p = T;s.push(T);while(!s.empty()){p = s.front();s.pop();cout<<p->data<<" ";if(p->left_child){s.push(p->left_child);}if(p->right_child){s.push(p->right_child);}}}int main(){
char array[]= "abce***d**mn*k**o*jh***";
BiTreeNode*T;
// create_T(T,array);

CreateBiTree(T,array);//pre_order
cout<<"pre_order_traverse"<<endl;
pre_order_traverse(T);
cout<<endl;
cout<<"pre_order_traverse_no_recurse"<<endl;
pre_order_traverse_no_recurse(T);
cout<<endl;//in_order
cout<<"in_order_traverse"<<endl;
in_order_traverse(T);
cout<<endl;
cout<<"in_order_traverse_no_recurse"<<endl;
in_order_traverse_no_recurse(T);
cout<<endl;//pos_order
cout<<"pos_order_traverse"<<endl;
pos_order_traverse(T);
cout<<endl;
cout<<"pos_order_traverse_no_recurse"<<endl;
pos_order_traverse_no_recurse(T);
cout<<endl;//层次遍历
BFS(T);return 0;
}