C语言学习笔记：链表（二）

链表的函数

• 示例：

  用链表读入学生名次和成绩然后输出

#include 
#include 
typedef struct stud{
 	char name[10];
 	int num;
 	float score;
 	struct stud *next;
}student;
student *creat(int n)；
void output(student* head)；
int main()
{
 	student *head;
 	int n;
 	printf("please input n:");
 	scanf("%d",&n);
 	head=creat(n);
 	output(head);
}
/*链表创建的函数*/
student *creat(int n)
{
 	student *head,*p,*q;
 	int i;
 	if(n>0){
  		head=(student*)malloc(sizeof(student));
  		printf("Please input the NO.1 name,num,sore:");
  		scanf("%s%d%f",head->name,&head->num,&head->score);
  		p=head;
  	for(i=2;i<=n;i++){
   		q=(student*)malloc(sizeof(student));
   	printf("Please input the NO.%d name,num,sore:",i);
   	scanf("%s%d%f",q->name,q->num,q->score);
   	p->next=q;
   	p=q;
  }
  	q->next=NULL;
 }
 	else
  		head=NULL;
 	return head; 
}
/*链表输出的函数*/
void output(student* head)
{
 	student *p;
 	p=head;
 	while(p!=NULL)
 {
  	printf("%s,%d,%f\n",p->name,&p->num,&p->score);
  	p=p->next;
 }

链表的查找

      在链表中查找某位成员值为给定值的结点历遍+比较,返回值为指针类型（指向查到结点的指针）

struct stud *find(struct stud *p)
{
 	long num;
 	printf("请输入你要查找的学号：");
 	scanf("%ld",&num);
 	while(p!=NULL){
  		if(p->num == num)
   			return p;
	   		p->next;
	}
 	return NULL;
}

链表的删除

   在链表中删除某位成员值为所给值的结点 历遍+比较+删除

student *_delete(student *head,int x)
{
 	student *p,*pre;
 	pre = p = head;
 	while(p!=NULL&&p->num!=x){
  	pre=p;
  	p=p->next;
 	}
 	if(p->num==x){
  	    if(p==head)
   		   head=p->next;
  	    else
  		   pre->next=p->next;
  	    free(p);
 }

链表的增加

student *insert(student *head) 
{
 	student *p,*q;
 	q=(student*)malloc(sizeof(student));
 	printf("please input the name,num,score:");
 	scanf("%s%d%f",q->name,&q->num,&q->score);
 	q->next=NULL;
 	if(head==NULL)
  	head=q;
 	else{
  		p=head;
  		if(head->num>q->num){
   			q->next=head;
   			head=q;
   			return head;
  		}
  		while(p->next!=NULL&&p->next->num<q->num)
  			p=p->next;
  		if(p->next!=NULL&&p->next->num==q->num) 
   			free(q);
  		else if(p->next==NULL)
   			p->next=q;
 		else{
   			q->next=p->next;
   			p->next=q;
  		} 
 	}
 	return head;
}