DS二叉树--层次遍历

#include <iostream>
#include <string>
#include <queue>
using namespace std;
class BiTreeNode {
public:
    char  data;					//数据域
    BiTreeNode  *leftChild,  *rightChild;	//左右子树指针
    BiTreeNode():leftChild(NULL), rightChild(NULL){}
    ~BiTreeNode() {}
};

class BiTree {
private:
    BiTreeNode *root;	//根结点指针
    string sTree;		//建树字符串
    int pos;			//标识建树字符串的当前字符位置
    BiTreeNode * CreateTree();//建树私有函数
public:
    BiTree():root(NULL) {};
    void Create(string vArray);	//建树公有接口，参数是特定的先序遍历字符串
    void LevelOrder();
    void LevelOrder(BiTreeNode*T);
};
void BiTree::Create(string vArray)
{	pos=0;
    sTree.assign(vArray);	//把参数保存到内部字符串
    root = CreateTree();	//建树成功后root指向根结点
}
BiTreeNode* BiTree::CreateTree() {
    if(pos==sTree.size()||sTree[pos]=='0'){
        pos++;
        return NULL;
    }
    BiTreeNode*T=new BiTreeNode();
    T->data=sTree[pos++];
    T->leftChild=CreateTree();
    T->rightChild=CreateTree();
    return T;
}
void BiTree::LevelOrder() { LevelOrder(root);}
void BiTree::LevelOrder(BiTreeNode *T) {
    queue<BiTreeNode*>tq;
    BiTreeNode*p=T;
    if(p)
        tq.push(p);
    while(!tq.empty()){
        p=tq.front();
        tq.pop();
        if(p){
            cout<<p->data;
            tq.push(p->leftChild);
            tq.push(p->rightChild);
        }
    }
    cout<<endl;
}
int main()
{	int t;
    string vArray;
    cin>>t;
    while(t--)
    {	cin>>vArray;
        BiTree myTree;
        myTree.Create(vArray);
        myTree.LevelOrder();
    }
    return 0;
}