（四川大学出版社C语言程序设计第二版课后习题）学生信息：学号，成绩，读出形成链表，查找某个学号的学生，将其成绩替换成新的成绩

#include
#include
#include

#define P 3     //学生人数
#define LEN sizeof(struct Student)   //结构体长度，方便后面为其分配空间

struct Student *Create();             //创建链表
void Print(struct Student *head);    //输出链表
void Fang(struct Student **head);    //释放链表
void Seek(struct Student *head);     //查找替换

struct Student
{
	char xh[12];
	float cj;
	struct Student *next;     
};

int main()
{
	struct Student *head;
	head=Create();
	Seek(head);
	printf("替换成绩后学生信息如下:n");
	Print(head);
	Fang(&head);
	return 0;
}

struct Student *Create()
{
	struct Student *head=NULL,*p,*p1;;
	int i=0;
	while(ixh ,&p->cj  );
	    p->next =NULL;
		i++;
		if(head==NULL)
		{
			head=p;
			p1=p;
		}
		else
		{
			p1->next=p;
			p1=p;
		}
	}
	return head;
}

void Print(struct Student *head)
{
	struct Student *p;
	p=head;
	while(p!=NULL)
	{
		printf("%s,%.1fn",p->xh ,p->cj  );
		p=p->next ;
	}
}
void Fang(struct Student **head)
{
	struct Student *p;
	while(*head!=NULL)
	{
		p=*head;
		*head=(*head)->next ;
		free(p);
	}
	*head=NULL;
}

void Seek(struct Student *head)
{
	struct Student *p;
	p=head;
	char x[12];
	float c;
	printf("请输入要替换成绩的同学的学号:n");
	scanf("%s",x);
	while(p!=NULL)
	{
		if(strcmp(p->xh,x)==0)
		{
			printf("请输入要替换的成绩:n");
			scanf("%f",&c);
			p->cj =c;
			break;
		}
		else
			p=p->next; 
	}
}