二级c公共基础篇64921738.pptVIP

2.3 linked lists The drawback of the static date structure 1.Once memory space is allocated for the array, it cannot be extended. 2.If some data item has to be inserted or if some data has to be removed from the array in the middle,bconsiderable amount of date of data movement occurs. this data movement consumes computer time and decreases program efficiency. To overcome this problem of static data structure,，a linked –list data structure is used. Linked-lists In the linked-list data structure, the elements need not be stored in consecutive memory locations. The memory space allocated for the elements of the list can be extended at any time. Each element will have two types of fields, namely, data fields and pointer fields. data fields have the actual data, the pointer fields has the address of the next element. Definition A linked list is an order collection of finite homogeneous data elements called nodes where the linear order is maintained by means of links or pointers. The number of pointers are maintained depending on the requirements and usage.based on this ,linked lists are classified into three categories: Singly linked list Doubly linked list Circularly linked list Singly linked list 2.3.2 basic operations 【2.6】InsertFirstLinkList Creat_LinkList1( ){ LinkList H=(LinkList)malloc(sizeof(LNode)); /* 生成头结点 */ H -next=NULL； /* 空表 */ LNode *s; int x; /* 设数据元素的类型为int */ scanf(＂%d＂,x); while (x!=-1)  { s=(LinkList)malloc(sizeof(LNode)); s-data=x; s-next=H-next; H-next=s; scanf (＂%d＂,x); } return H ; } (2)Inserts a node after the last node of the linked list （16，20，65，12） 【2.7】InsertLast The length of list 算法思路：设一个指针ｐ和计数器ｊ，初始化使ｐ指向头结点H，ｊ=0。若ｐ所指结点还有后继结点，ｐ向后移动，计数器加 1，重复上述过程，直到p-next==NULL为止。 【算法2.8】设H是带头结点的单链表，求带头结点单链表的表长。 Status Length_LinkList (LinkList H) { LNode * p= H ; int j=0; while(p-next) { p=p-next; j++； } return j; } 4．Insertion of a node int I