二叉树遍历-非递归-Cpp代码-前序

#include<iostream>
#include<stack>
using namespace std;  

//定义二叉树结点链式存储结构
struct BiTNode{
        int data;//数据域
        struct BiTNode *lchild,*rchild;//左右孩子指针
}*BiTree;

//前序遍历函数声明
int PreOrder(struct BiTNode *BiTree);

int main()  
{
        //初始化结点
        struct BiTNode node1,node2,node3,node4,node5,node6,node7,node8,node9,node10,node11;
        node1=(struct BiTNode){1,&node2,&node3};
        node2=(struct BiTNode){2,&node4,&node5};
        node3=(struct BiTNode){7,&node6,&node7};
        node4=(struct BiTNode){3,NULL,&node8};
        node5=(struct BiTNode){6,NULL,NULL};
        node6=(struct BiTNode){8,NULL,NULL};
        node7=(struct BiTNode){9,&node9,NULL};
        node8=(struct BiTNode){4,&node10,NULL};
        node9=(struct BiTNode){10,NULL,&node11};
        node10=(struct BiTNode){5,NULL,NULL};
        node11=(struct BiTNode){11,NULL,NULL};

        //建树
        BiTree=&node1;

        PreOrder(BiTree);
        cout << endl;
        return 0;  
}

//前序遍历-非递归实现
int PreOrder(struct BiTNode *BiTree){
        stack<struct BiTNode*> s;
        struct BiTNode *p;//遍历指针
        p=BiTree;
        s.push(p);
        if(BiTree==NULL){return 0;}
        while(!s.empty()){
                //cout << "压栈：" << p->data << endl;
                p=s.top();
                cout << p->data << " ";
                s.pop();
                if(p->rchild)s.push(p->rchild);
                if(p->lchild)s.push(p->lchild);
        }
        return 0;
}