#include <iostream>
using namespace std;
class Node{
private:
int val1;
double val2;
Node *next;
Node *pre;
public:
Node(){
next = NULL;
pre = NULL;
};
Node(int x1, double x2){
next = NULL;
pre = NULL;
val1 = x1;
val2 = x2;
}
void SetNext(Node *n){
next = n;
};
Node *GetNext(){
return next;
}
void SetPre(Node *n){
pre = n;
}
Node *GetPre(){
return pre;
}
int getVal1(){
return val1;
}
double getVal2(){
return val2;
}
};
template<class Node>
class Iterator{
public:
Iterator() {};
virtual ~Iterator() {};
virtual Node* first() = 0;
virtual Node* last() = 0;
virtual Node* next() = 0;
virtual Node* pre() = 0;
virtual Node* nowPos() = 0;
virtual int len() = 0;
virtual void SetDirect(bool s) = 0;
};
template<class Node>
class Aggregate{
public:
Aggregate() {};
virtual ~Aggregate() {};
virtual Iterator<Node>* createIterator() = 0;
virtual Node* GetFirst() = 0;
virtual Node* GetLast() = 0;
virtual int GetSum() = 0;
virtual void Insert(int a, double b) = 0;
virtual void Init() = 0;
};
template<class Node>
class ConcreteIterator : public Iterator<Node>{
public:
ConcreteIterator(Aggregate<Node> *a) :aggr(a){
cur = aggr->GetFirst()->GetNext();
};
~ConcreteIterator() {};
Node* first(){
Node * p = new Node();
p = aggr->GetFirst()->GetNext();
return p;
}
Node* last(){
Node * p = new Node();
p = aggr->GetLast();
return p;
}
Node* pre(){
Node * p = cur->GetPre();
cur = cur->GetPre();
return p;
}
Node* nowPos(){
return cur;
}
Node* next(){
Node * p = cur->GetNext();
cur = cur->GetNext();
return p;
}
void SetDirect(bool s){
if(s){
cur = aggr->GetFirst()->GetNext();
}else{
cur = aggr->GetLast();
}
}
int len(){
return aggr->GetSum();
}
private:
Aggregate<Node> *aggr;
Node* cur;
};
template<class Node>
class LinkList : public Aggregate<Node>{
private:
Node* first;
Node* last;
int sum;
public:
Iterator<Node>* createIterator(){
return new ConcreteIterator<Node>(this);
}
LinkList(){
first = NULL;
last = NULL;
sum = 0;
}
Node* GetFirst(){
return first;
}
Node* GetLast(){
return last;
}
int GetSum(){
return sum;
}
void Init(){
first = new Node();
}
void Insert(int a, double b){
Node *p = first;
Node *s = new Node(a, b);
for (int i = 0; i < sum; i++){
p = p->GetNext();
}
s->SetNext(NULL);
s->SetPre(p);
p->SetNext(s);
last = s;
sum++;
}
~LinkList(){}
};
int main(){
Aggregate<Node> * aggr = new LinkList<Node>();
aggr->Init();
aggr->Insert(1, 2.1);
aggr->Insert(2, 4.2);
aggr->Insert(3, 6.3);
aggr->Insert(4, 8.4);
aggr->Insert(8, 16.5);
Iterator<Node> * it = aggr->createIterator();
cout<<"正序"<<endl;
it->SetDirect(true);
while(it->nowPos()!= NULL){
cout<<it->nowPos()->getVal1()<<" "<<it->nowPos()->getVal2()<<endl;
it->next();
}
cout<<"倒序"<<endl;
it->SetDirect(false);
do{
cout<<it->nowPos()->getVal1()<<" "<<it->nowPos()->getVal2()<<endl;
it->pre();
}while(it->nowPos()!= it->first()->GetPre());
return 0;
}
