层序遍历及其进阶版

输入为：abd##eh###cfi##j##g##

1、普通层序遍历：输出为一行

2、进阶版1：输出每一层，从左向右依次输出

3、进阶版2：S型输出每一层，即从右向左和从左向右交替输出

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

template<class T>
struct BiNode  
{  
    T data;
	BiNode<T>* leftchild,*rightchild;
}; 

template<class T>  
class BiTree  
{  
public:  
    BiTree(); 
	BiNode<T>* GetRoot();
	void PreOrder(BiNode<T>* node);
    void LevelOrder1(BiNode<T>* node);//层次遍历 
	void LevelOrder2(BiNode<T>* node);//高级版层序遍历
	void LevelOrder3(BiNode<T>* node);//螺旋版层序遍历
private:  
    BiNode<T>* m_root;  
    BiNode<T>* Create();  
};  
template<class T>  
BiNode<T>* BiTree<T>::GetRoot()  
{  
    return m_root;  
}  
  
template<class T>  
BiTree<T>::BiTree()  
{  
    m_root = new BiNode<T>;  
    m_root = Create();  
  
}    
template<class T>  
BiNode<T>* BiTree<T>::Create()  
{  
    char ch;  
    cin>>ch;  
    BiNode<T>* pnode;  
    if (ch == '#')   
        pnode = NULL;  
    else  
    {  
        pnode = new BiNode<T>;  
        pnode->data = ch;  
        pnode->leftchild = Create();  
        pnode->rightchild = Create();  
    }  
    return pnode;  
}  
/*template<class T>
void BiTree<T>::PreOrder(BiNode<T>*R){
	if(R){
		cout<<R->data<<' ';
		PreOrder(R->leftchild);
		PreOrder(R->rightchild);
	}
}*/
template<class T>
void BiTree<T>::LevelOrder1(BiNode<T>* R){//普通版
	BiNode<T> * queue[100];
	BiNode<T> * p;
	int f=0,r=0;
	if(R)
		queue[++r]=R;
	while(f!=r){
		p=queue[++f];
		cout<<p->data;
		if(p->leftchild)
			queue[++r]=p->leftchild;
		if(p->rightchild)
			queue[++r]=p->rightchild;
	}
}
template<class T>
void BiTree<T>::LevelOrder2(BiNode<T>* R){//进阶版1
	if(R){
		vector<BiNode<T> *> vec;
		vec.push_back(R);
		int f=0,r=1;
		while(f<vec.size()){
			r=vec.size();
			while(f<r){
				cout<<vec[f]->data<<' ';
				if(vec[f]->leftchild)
					vec.push_back(vec[f]->leftchild);
				if(vec[f]->rightchild)
					vec.push_back(vec[f]->rightchild);
				f++;
			}
			cout<<endl;
		}
	}
}
template<class T>
void BiTree<T>::LevelOrder3(BiNode<T>* R){//进阶版2
	if(R){
		vector<BiNode<T> *> vec;
		vec.push_back(R);
		int f=0,r=1,s=1;
		int check=0;
		while(f<vec.size()){
			r=vec.size();
			check=1-check;
			int r1=r;
			while(f<r1){
				if(check){
					cout<<vec[f]->data<<' ';
					if(vec[r-1]->rightchild){
						vec.push_back(vec[r-1]->rightchild);}
					if(vec[r-1]->leftchild){
						vec.push_back(vec[r-1]->leftchild);}
					f++;
					r--;}
				else{
					cout<<vec[f]->data<<' ';
					if(vec[r-1]->leftchild){
						vec.push_back(vec[r-1]->leftchild);}
					if(vec[r-1]->rightchild){
						vec.push_back(vec[r-1]->rightchild);}
					f++;
					r--;
				}
			}
			cout<<endl;
		}
	}
}

int main()  
{  
    BiTree<char> mtree;  
	//cout<<"PreOrder:"<<endl;
	BiNode<char> *root=mtree.GetRoot();
	//mtree.PreOrder(root);
	cout<<"LevelOrder:"<<endl;
	mtree.LevelOrder3(root);
	system("pause");
	return 0;  
}  

层序遍历及其进阶版

原文：http://blog.csdn.net/eliza1130/article/details/44418527