二叉樹

#include <iostream>
using namespace std;
#include <iomanip>
typedef char T;
class bst{
	struct Node{
		T data;
		Node* L;
		Node* R;
		Node(const T& d):data(d),L(),R(){}
		Node(const T& d,Node*l,Node*r):data(d),L(l),R(r){}
	};
	typedef Node* tree;
	Node* rp;
	int n;
public:
	bst():rp(),n(){}
	void clear(){clear(rp);n=0;}
	~bst(){clear();}
	void insert(const T& d){insert(rp,new Node(d));++n;}
	tree& find(const T& d){return find(rp,d);}
	void travel()const{travel(rp);cout<<endl;}
	bool empty()const{return rp==NULL;}
	bool remove(const T& d){
		tree& t = find(d);
		if(t==NULL) return false;
		Node* p = t;
		if(t->L!=NULL) insert(t->R, t->L);
		t = t->R;
		delete p;
		--n;
		return true;
	}
	const T& root()const{if(!rp) throw"空";return rp->data;}
	int size()const{return n;}
	void update(const T& olddata,const T& newdata){
		if(remove(olddata)) insert(newdata);
	}
	void insert(tree& t, Node* p){
		if(t==NULL) t = p;
		else if(p->data < t->data) insert(t->L,p);
		else insert(t->R,p);
	}
	tree& find(tree& t, const T& d){//返回以d爲根的子樹的根指針
		if(t==NULL) return t;//沒找到
		else if(d==t->data) return t;//找到了
		else if(d<t->data)	return find(t->L,d);
		else return find(t->R,d);
	}
	void travel(tree t)const{
		if(t!=NULL){
			travel(t->L);
			cout << t->data << ' ';
			travel(t->R);
		}
	}
	void clear(tree& t){
		if(t!=NULL){
			clear(t->L);
			clear(t->R);
			delete t; t=NULL;
		}
	}
	int high(tree t){
		if(t==NULL) return 0;
		int lh = high(t->L);
		int rh = high(t->R);
		return 1+(lh>rh?lh:rh);
	}
	void print(tree t, int space, char sign){
		if(t==NULL) return;
		print(t->R,space+3,'/');
		cout << setw(space+1) << sign << t->data << endl;
		print(t->L,space+3,'\\');
	}
	void print(){ print(rp,0,'*');cout<<"---------"<<endl; }
};
int main()
{
	bst b;
	b.insert('k');b.insert('s');b.insert('f');b.insert('t');
	b.insert('a');b.insert('m');b.insert('x');b.insert('e');
	b.insert('w');b.insert('b');b.insert('u');b.insert('j');
	b.print();
	b.remove('k');b.remove('m');b.remove('j');b.remove('u');
	b.print();
	b.update('b','k');b.update('k','b');b.update('x','*');
	b.print();
	while(!b.empty()) b.remove(b.root());
	cout<<"size:"<<b.size()<<endl;
	b.print();
}