例25 删除指定的节点
struct student *del(struct student *head, long n){structstudent*p1,*p2;/*↑n：要删除学号*/p1=head;
if(p1->num==n)head=p1->next;/*删除首节点*/else
{do{p2=p1;p1=p1->next;
}while(p1!=NULL&&p1->num!=n);if(p1->num==n)p2->next=p1->next;/*找到*/elseprintf(\befound!\\n\/*未找到*/}
free(p1);/*释放被删除节点的存储区*/return(head);/*返回头指针*/}
例26 在链表中插入节点的函数：
structstudent*insert(structstudent*head)
{structstudent*p0,*p1,*p2;longn;intlen;
len=sizeof(structstudent);
p0=(structstudent*)malloc(len);/*申请新节点*/printf(\
scanf(\&p0->num,&p0->score);n=p0->num;/*产生学号副本n*/p1=head;/*从首节点开始查找*/
┇
┇p1=head;/*↓插入在头部*/if(n
{ do /*查找插入位置*/{ p2=p1;
p1=p1->next;
} while(p1!=NULL && n>p1->num);
p0->next=p2->next; /*插入在其余位置*/p2->next=p0;}
return(head);
} /*insert*/