1.5求两个整数集合并集

/************************************
*
*          c++程序设计实践指导
*
*          1.5求两个整数集合并集
*
*************************************/
#include <iostream>
using namespace std;
class SET
{
	struct LinkNode		//单链表节点数据结构
	{
		int data;
		LinkNode *next;
	};
	LinkNode *head1, *head2, *head3;		//3个单链表
	int num1, num2, num3;		//3个表长
public:
		SET(int *x, int len1, int *y, int len2)		//构造函数，用len1初始化num1，用len2初始化num2
		{
			head1 = new LinkNode;
			head1->data = -1;
			head1->next = NULL;
			head2 = new LinkNode;
			head2->data = -1;
			head2->next = NULL;
			head3 = new LinkNode;
			head3->data = -1;
			head3->next = NULL;
			LinkNode *p1, *p2;
			p1 = head1;
			p2 = head2;
			for(int i =  0; i < len1; i++)
			{
				LinkNode *s = new LinkNode;
				s->data = x[i];
				s->next = NULL;
				p1->next = s;
				p1 = s;
			}
			for(int i = 0; i < len2; i++)
			{
				LinkNode *s = new LinkNode;
				s->data = y[i];
				s->next = NULL;
				p2->next = s;
				p2 = s;
			}
			num1 = len1;
			num2 = len2;
		}
		int notin(int elem, LinkNode *q)		//若elem不在以q为头节点的单链表中则返回1，不然，返回0
		{
			LinkNode *p = q->next;
			while(p)
			{
				if(elem == p->data) 
					return 0;
				p = p->next;
			}
			return 1;
		}
		void insert();		//完成求两集合并集的功能
		void desert();		//完成求两集合交集的功能
		void show()
		{
			LinkNode *p = head3->next;
			while(p)
			{
				cout << p->data << "    ";
				p = p->next;
			}
			cout << endl;
			cout << "新的集合元素个数是 ：" << num3 <<endl;
		}
};
void SET::insert()		//求两集合并集
{
	LinkNode *p1 = head1->next;
	LinkNode *p2 = head2->next;
	LinkNode *p, *q;
	q = head3;
	while(p1)		//先将单链表1中的元素复制到单链表3中
	{
		p = new LinkNode;
		p->data = p1->data;
		p->next = NULL;
		q->next = p;
		q = p;
		p1 = p1->next;
	}
	num3 = num1;
	while(p2)		//将在单链表2中而不在单链表1中的元素复制到单链表3中
	{
		if(notin(p2->data, head3))
		{
			p = new LinkNode;
			p->data = p2->data;
			p->next = NULL;
			q->next = p;
			q = p;
			++num3;
		}
		p2 = p2->next;
	}
}
void SET::desert()		//求交集
{
	LinkNode *p1 = head1->next;
	LinkNode *p2 = head2->next;
	LinkNode *p, *q;
	q = head3;
	num3 = 0;
	while(p2)		//将单链表2与单链表1比较，二者均有的元素加入单链表3中
	{
		if(notin(p2->data,head1) == 0)
		{
			p = new LinkNode;
			p->data = p2->data;
			p->next = NULL;
			q->next = p;
			q = p;
			++num3;
		}
		p2 = p2->next;
	}

}
int main()
{
	int s1[] = {1,3,5,7,9};
	int s2[] = {2,4,6,9};
	SET set(s1, sizeof(s1)/sizeof(s1[0]), s2, sizeof(s2)/sizeof(s2[0]));
	cout << "并集：";
	set.insert();
	set.show();
	cout << "交集：";
	set.desert();
	set.show();
	system("pause");
	return 0;
}