基于栈的非递归方法实现二叉树

#include<iostream>#include<vector>#include<stdlib.h>using namespace std;struct BiNode{    char data;    struct BiNode *left;    struct BiNode *right;};typedef struct BiNode Node;typedef Node* LinkNode;//以先序的顺序编写结点LinkNode CreatTree(LinkNode T){    char temp;    cin>> temp;    if('0' == temp)    {        T = NULL;    }    else    {        T = (LinkNode)malloc(sizeof(Node));        T->data = temp;        T->left = CreatTree(T->left);        T->right = CreatTree(T->right);    }    return T;}//非递归前序void PreOrder(LinkNode T){    if(T == NULL)    {        return;    }    vector<LinkNode> s;    LinkNode p = T;    while(p != NULL || !s.empty())    {        while(p != NULL)    {        cout<<p->data;        s.push_back(p);        p = p ->left;    }    if(!s.empty())    {        p = s[s.size()-1];        s.pop_back();        p = p->right;    }    }}void InOrder(LinkNode T){    if(NULL == T)    {        return;    }    vector<LinkNode> s;    LinkNode p = T;    while(p != NULL || !s.empty())    {        while(p != NULL)    {        s.push_back(p);        p = p->left;    }    if(!s.empty())    {        p= s[s.size()-1];        cout<<p->data;        s.pop_back();        p = p->right;    }    }}/*具体思路：栈S1 和S2 。首先根节点入栈S1，当S1不为空弹出栈顶元素，并入栈S2，如果说弹出的左右子树不为空，则依次将其左子树和右子树入栈。直到栈S1空时停止。/i/*/void PostOrder(LinkNode T){    if(NULL == T)    {        return;    }    vector<LinkNode> s1,s2;    LinkNode p = T;    s1.push_back(T);    while(!s1.empty())    {        p = s1[s1.size()-1];        s1.pop_back();    s2.push_back(p);    if(p->left != NULL)    {        s1.push_back(p->left);    }    if(p->right != NULL)    {        s1.push_back(p->right);    }    }    while(!s2.empty())    {        p = s2[s2.size()-1];    cout<<p->data;    s2.pop_back();    }}int main(){    Node *Tree;    Tree = CreatTree(Tree);    cout<<"前序序列:"<<endl;    PreOrder(Tree);    cout<<endl;    cout<<"中序序列:"<<endl;    InOrder(Tree);    cout<<endl;    cout<<"后序序列:"<<endl;    PostOrder(Tree);    cout<<endl;}

运行结果