有两个链表a和b，设结点中包含学号、姓名。从a链表中删去与b链表中有相同学号的那些结点。

有两个链表a和b，设结点中包含学号、姓名。从a链表中删去与b链表中有相同学号的那些结点。

方法一：（链表删除操作得动态初始化链表，其余操作动态初始化或静态初始化链表都行）

#include 
#include 

//声明结构体struct Student
struct Student
{                                       
    int num;
    char name[20];
	struct Student *prev;
    struct Student *next;
};

struct Student *input(int n);//声明输入函数
void append(struct Student **head2, struct Student *stu);//声明建立链表操作 
void del_list(struct Student **, struct Student *);//声明删除两个链表中重复的多个节点函数
void del_item(struct Student **, struct Student *);//声明删除单个节点函数
void print(struct Student *);//声明输出函数操作 

int main()
{
	struct Student *a,*b;
	a=input(3);                                            //调用输入函数，生成a链表
	print(a);
	b=input(2);                                            //调用输入函数，生成b链表
	del_list(&a, b);                                     //从a中删除b
	print(a);
    return 0;
}

//输入函数
struct Student *input(int n)
{
	struct Student *head = NULL, *stu;
	
    for (int i=1; i<=n; i++)//动态初始化链表 
	{
		stu	= (struct Student*)malloc(sizeof(struct Student));
        printf("Please enter No.%d student info: ", i);
        scanf("%d %s", &stu->num,stu->name);
		append(&head, stu);
    }
	printf("\n");
	return head;
}

//建立链表操作 
void append(struct Student **head2, struct Student *stu) 
{	
	stu->next = NULL;	
	if (*head2 == NULL) 
	{
		stu->prev = NULL;
		*head2 = stu;
	}
	else 
	{
		struct Student *p = *head2;
		while (p->next!=NULL)
			p=p->next;
		p->next = stu;
		stu->prev = p;
	}
}

//删除多个节点函数
void del_list(struct Student **list1, struct Student *list2)
{
    struct Student *p, *q, *next;
		
	for (q=list2; q!=NULL; q=q->next) 
	{
		for (p=*list1; p!=NULL; p=p->next) 
		{	
        	if (p->num == q->num) 
			{
				del_item(list1, p);
            }
		}	
	}
}

//删除单个节点函数
void del_item(struct Student **head, struct Student *p)
{
	if (p==*head)
		*head=p->next;
	if (p->prev!=NULL)
		p->prev->next=p->next;			
	if (p->next!=NULL)
		p->next->prev=p->prev;
	free(p);
}

//输出函数
void print(struct Student *stu)
{
	if(stu == NULL)
		printf("Empty Linked list.\n");
	else 
	{
		struct Student *p;
		for (p=stu; p!=NULL; p=p->next) 
		{
			printf("%d %s\n", p->num, p->name);
		}		
	}
}

方法一简化版：（简化input函数)

#include 
#include 

//声明结构体struct Student
struct Student
{                                       
    int num;
    char name[20];
	struct Student *prev;
    struct Student *next;
};

struct Student *input(struct Student *stu, int n);//声明输入函数
void del_list(struct Student **, struct Student *);//声明删除两个链表中重复的多个节点函数
void del_item(struct Student **, struct Student *);//声明删除单个节点函数
void print(struct Student *);//声明输出函数操作 

int main()
{
	struct Student *a=(struct Student*)malloc(3*sizeof(struct Student));//相当于struct Student a[3]
	struct Student *b=(struct Student*)malloc(2*sizeof(struct Student));//相当于struct Student b[3]
	a=input(a, 3);                                            //调用输入函数，生成a链表
	print(a);
	b=input(b, 2);                                            //调用输入函数，生成b链表
	del_list(&a, b);                                     //从a中删除b
	print(a);
	free(a);
	free(b);
    return 0;
}

//输入函数
struct Student *input(struct Student *stu, int n)//先建立两个链表 
{
	int i=0;
	struct Student *p;
	for (p=stu; p<stu+n; p++, i++)
	{
		printf("Please enter No.%d student info; ", i+1);
		scanf("%d %s", &p->num, p->name);
		i==0?(p->prev=NULL):(p->prev=&stu[i-1]);
		i==n-1 ? (p->next=NULL) : (p->next=&stu[i+1]);
	}
	return stu; 
}

//删除多个节点函数
void del_list(struct Student **list1, struct Student *list2)
{
    struct Student *p, *q, *next;
		
	for (q=list2; q!=NULL; q=q->next) 
	{
		for (p=*list1; p!=NULL; p=p->next) 
		{	
        	if (p->num == q->num) 
			{
				del_item(list1, p);
            }
		}	
	}
}

//删除单个节点函数
void del_item(struct Student **head, struct Student *p)
{
	if (p==*head)
		*head=p->next;
	if (p->prev!=NULL)
		p->prev->next=p->next;			
	if (p->next!=NULL)
		p->next->prev=p->prev;
}

//输出函数
void print(struct Student *stu)
{
	if(stu == NULL)
		printf("Empty Linked list.\n");
	else 
	{
		struct Student *p;
		for (p=stu; p!=NULL; p=p->next) 
		{
			printf("%d %s\n", p->num, p->name);
		}		
	}
}