实验3：双链表

#include<iostream>
using namespace std;
const int maxsize = 10;

struct Node
{
	double data;
	Node *prior, *next;
};

class scorelist
{
private:
	Node * p;
public:
	scorelist()
	{
		p = new Node;
		p->next=NULL ;
	}
	~scorelist()
	{
		Node *q = NULL;
		while (p != NULL)
		{
			q = p;
			p = p->next;
			delete p;
		}
	}
	scorelist(double a[], int n)
	{
		Node *r, *s;
		p = new Node;
		r = p;
		for (int i = 0; i < n; i++)
		{
			s = new Node;
			s->prior = r;
			s->data = a[i];
			r->next = s;
			r = s;
		}
		r->next = NULL;
	}
	void insert(int i, double x)
	{
		Node *o = p, *s = NULL;
		int count = 0;
		while (o != NULL && count < i - 1)
		{
			o = o->next;
			count++;
		}
		if (o == NULL) throw"位置异常";
		else
		{
			s = new Node;
			s->data = x;
			s->prior = o;
			s->next = o->next;
			(o->next)->prior = s;
			o->next = s;
		}
	}
	void printlist()
	{
		Node *o = p->next;
		while (o != NULL)
		{
			cout << o->data << " ";
			o = o->next;
		}
		cout << endl;
	}
};
void main()
{
	double stu[6] = { 25,65,75,85,95,100 };
	scorelist student(stu,6);
	student.printlist();
	student.insert(3, 60);
	cout << "插入成绩后的列表：" << endl;
	student.printlist();
}