원형리스트 덧셈하는건데요..

우선 숙제임을 밝혀둡니다 -_-;;

하다하다 도저히 막혀서 이렇게 올리네요

코드는 아래와 같습니다.

다항식 2개를 입력받아

연산자 오버로딩으로

두 다항식의 합을 출력하는건데

vc6 에서 컴파일 했을 경우

두 다항식의 입력과 출력은 되는데

그 합을 출력하는 부분에서 멈춰버립니다.

며칠밤을 고민했는데도 도대체 뭐가 문제인지

감이 안 잡힙니다. 도움 좀 주세요 :oops:

#include <iostream.h>

struct Term {
	int exp;
	int coef;
	void Init(int c, int e){coef = c; exp = e;};
};

class List;
class CircListIterator;

class ListNode {
	friend class List;
	friend class CircListIterator;
	public:
		ListNode(Term k) {
			data = k;
			link = 0;
		};
	private:
		Term data;
		ListNode *link;
};

class List {
	friend class CircListIterator;
	public:
		void Attach(Term k);
		List() {
			first = 0;
			last = 0;
		};
		~List();
	private:
		ListNode *first;
		ListNode *last;
		ListNode *head;
};

List::~List() {
	ListNode* next;
	ListNode* now;
	now = head;
	next = head;
	while(true){
		next = next->link;
		delete now;
		if(next == NULL) break;
		now = next;
	}
}

void List::Attach(Term k){
	ListNode *newnode = new ListNode(k);
	if(first==0){
		Term a;
		a.Init(0,-1);
		ListNode *node = new ListNode(a);
		first = newnode;
		last = newnode;
		head = node;
		head->link = first;
		newnode->link = head;
	} else {
		last->link = newnode;
		newnode->link = head;
		last = newnode;
	}
}

class CircListIterator {
	public:
		CircListIterator(const List& l):list(l), current(l.first){};
		bool NotNull() {
			if(current) return true;
			else return false;
		};
		bool NextNotNull() {
			if(current && current->link) return true;
			else return false;
		};
		Term* First() {
			if(list.first) return &list.first->data;
			else return 0;
		}
		Term* Next() {
			current = current->link;
			return &current->data;
		};
	private:
		const List& list;
		ListNode* current;
};

class Polynomial{
	private:
		List poly;
	public:
		Polynomial(){};
		Polynomial(const Polynomial &);
		friend Polynomial operator+(const Polynomial&, const Polynomial&);
		friend istream& operator>>(istream&, Polynomial&);
		friend ostream& operator<<(ostream &, const Polynomial &);
};

Polynomial::Polynomial(const Polynomial &a){
	Term *p, *q, temp;
	CircListIterator iter(poly);
	CircListIterator iter2(a.poly); 
	p = iter.First();
	q = iter2.First();
	while (iter.NotNull()) {
		temp.Init(0,-1);
		poly.Attach(temp);
		p = iter.Next();
	}
	while (iter2.NotNull()) {
		temp.Init(q->coef,q->exp); 
		poly.Attach(temp);
		q = iter2.Next();
	}
}

char compare(int x, int y) {
	if(x == y) return '=';
	else if(x < y) return '<';
	else return '>';
}

Polynomial operator+(const Polynomial& a, const Polynomial& b){
	Term *p, *q, temp;
	CircListIterator Aiter(a.poly);
	CircListIterator Biter(b.poly);
	Polynomial c;
	p = Aiter.First();q = Biter.First();
	while(1)
		switch( compare(p->exp, q->exp) ) {
			case '=':
				if( p->exp == -1 ) return c;
				else {
					int sum = p->coef + q->coef;
					if(sum) {
						temp.Init(sum, q->exp);
						c.poly.Attach(temp);
					}
					p = Aiter.Next();
					q = Biter.Next();
				}
				break;
			case '<':
				temp.Init(q->coef, q->exp);
				c.poly.Attach(temp);
				q = Biter.Next();
				break;
			case '>':
				temp.Init(p->coef, p->exp);
				c.poly.Attach(temp);
				p = Aiter.Next();
				break;
		}
}

istream& operator>>(istream& is, Polynomial& p){
	Term temp;
	int exp;
	int coef;
	char ch = ' ';
	while( ch != '\n')	{
		is >> coef >> exp;
		temp.Init(coef, exp);
		p.poly.Attach(temp);
		ch = is.get();
	}
	return is;
}

ostream& operator<<(ostream & os ,const Polynomial & a) {
	Term *p;
	CircListIterator iter(a.poly); 
	p = iter.First();
	while(!((p->exp) == -1)){
		if( p->coef > 0 && p!=iter.First() ) cout << " + ";
		cout << p->coef << "x^" << p->exp ; 
		p = iter.Next();
	}
		
	cout << endl;
	return os;
}

int main() {
	Polynomial A,B,C;

	cout <<"입력 예제 :  3x^14 + 2x^8 - 7x^3 + 1  ->  3 14 2 8 7 3 1 0 "<<endl;

	cout <<"\n A 다항식 : ";
	cin >> A;
	
	cout <<"\n B 다항식 : ";
	cin >> B;

	cout<<endl;

	cout<<"A = "<<A<<endl;
	cout<<"B = "<<B<<endl;

	C = A + B;

	cout<<"C = "<<C<<endl;

	return 0;
}