demo_struct_list_b.cpp

对于一个初涉VC＋＋的人来书

//***************************************************
//*************************************
//**         Struct_List_B.cpp       **
//*************************************
// 输入和创建链表，最后输出显示该链表

# include <iostream.h>
# include <stdlib.h>

//***************************************************
// 声明结构体
struct Student
{
	long number;
	float score;
	Student* next;
};

//***************************************************
// 定义创建链表的函数
Student* Create()
{
	Student* head;   // 链表的头指针

	Student* pS;     // 链表的结点指针
	Student* pEnd;   // 链表的尾指针 

	// 新建一个结点
	pS= new Student; // 动态申请一个结点内存空间
	if(pS==NULL)
	{
		cout<<"Can't allocate more memory,terminating.\n";
		exit(1);
	}

	cout<<"Input number and score of one item:\n";
	cin>>pS->number>>pS->score; // 给节点赋number和score值

	head=NULL; // 开始链表为空

	if(pS->number==0) // 若链表为空
	{
		delete pS;
		return head;
	}

	while(pS->number!=0) // 若链表为非空
	{
		if(head==NULL)
			head=pS;
		else
			pEnd->next=pS; // 给节点赋next值

		pEnd=pS;

		// 新建一个结点
		pS=new Student; // 动态申请一个结点内存空间
		if(pS==NULL)
		{
			cout<<"Can't allocate more memory,terminating.\n";
			exit(1);
		}

		cout<<"Input number and score of one item:\n";
		cin>>pS->number>>pS->score; // 给节点赋number和score值
	}

	pEnd->next=NULL; // 给节点赋next值

	delete pS;

	return head;
}

//***************************************************
// 定义遍历链表的函数
void ShowList(Student* head)
{
	if(!head)
	{
		cout<<"The list is null!\n";
		return;
	}

	cout<<"Output the items of list are \n";
	while(head)
	{
		cout<<head->number<<","<<head->score<<endl;
		head=head->next;
	}
	return;
}

//***************************************************
// 删除链表结点
Student* Delete(Student* head,long number)
{
	Student* p;

	// 若链表是空的
	if(!head) // head==NULL
	{
		cout<<"\nList null!\n";
		return head;
	}

	// 若删除的结点是第一个结点
	if(head->number==number)
	{
		p=head;
		head=head->next;
		delete p;
		cout<<number<<" have been deleted!\n";
		return head;
	} 

	// 若删除的结点不是第一个结点
	// 循环执行条件是: pGuard->next!=NULL
	for(Student* pGuard=head;pGuard->next;pGuard=pGuard->next)
	{
		if(pGuard->next->number==number)
		{
			p=pGuard->next; // 待删除的结点
			pGuard->next=p->next;
			delete p;
			cout<<number<<" have been deleted!\n";
			return head;
		}
	}

	cout<<number<<" not found!\n"; // 未找到要删除的结点
	return head;
}

//***************************************************
// 主程序创建并遍历链表
void main()
{
	Student* head;

	head=Create();
	ShowList(head);

	head=Delete(head,54);
	ShowList(head);
}

//***************************************************