单链表的学习心得

（1） ADT
typedef int ElemType
typedef struct Node{
ElemType data;
struct Node * next;
}Node;

typedef struct Node* linkList;

(2) int initList(linkList *L)

int initList(linkList *L)
{
     (*L) = (linkList)malloc(sizeof(Node));  
     (*L)->next = NULL;
     printf("create initial  successfully\n");
     return 1; 
}           

链表的插入。在那些函数中，我们无法使用简单赋值，因为变量名在函数的作用域内部是未知的。函数所拥有的只是一个指向需要修改的内存位置的指针，所以要对该指针进行间接访问操作以访问需要修改的变量。
(3) int createListHead(linkList *L,int n)

int createListHead(linkList *L,int n){
     linkList p;
     int i=0;
     srand((int)time(0));
      for( i = 0;i < n;i++)
    {
       p = (linkList malloc   sizeof(Node)；
       p ->data = rand() %100;
       printf("testing:Node[%d]=%d\n",i+1,p->data);
       p->next = (*L)->next;
       (*L)->next = p;            
     }
      printf("linklist(headinsert)  create successfully.\n");
      return 1;
    }                  

int createListTail(linkList *L,int n){
   linkList p,temp;
   temp = (*L);
   int i;
   srand((int)time(0));
    for( i = 0; i < n;i++){
     p = (linkList)malloc(sizeof(Node));    
     p->data = rand() % 100;    
     printf("testing:Node[%d]=%d\n",i+1,p->data);
     p->next = NULL;
     temp->next = p;
     temp = p;
 }
  printf("linklist(tail)create successfully);
   return 1;
}                     

(4)int getlength(linkList *L)

int getlength(linkList *L){
  linkList p;
  int length = 0;
  p = (*L)->next;
  while(p){
    length++;
     p = p->next;
   }
    return length;
}                   

(5) int printList(linkList *L)

int printList(linklist *L){
   linkList p;
    int i = 0;
    p = (*L) ->next;
   if(p == NULL){    
    printf("----------print the whole linklist----------\n");
}
 while(p){
  i++;
  printf("the %d node 's data is =%d\n",i,p->data);
   p=p->next;
  }
   return 1;
 }             

(6) int getElem(linkList *L,int i,ElemType *getdata)

int getElem(linkList *L,int i,ElemType *getdata){
linkList p;
p = (*L)->next;
if(p==NULL)
{
    printf("the linklist is empty,please create a linklist\n");
    *getdata = -1;
     return 0;
}

if( i < 1)
{
     printf("您所查询的节点%d，应该大于0，请重新输入查询\n",i);
     *getdata = -1;
       return 0;
}
 int j =1; 
 while(p&&j<1){       
    j++;
    p = p->next;
}

if(p == NULL)
{
    printf("the node you have queried %d has beyonded the length of array\n",i);
    *getdata = p->data;
    printf("search successfully!\n",i);        
    return 1;
}            
             

(7) Insert node
Insert node are classfied by two ways.
The first one is Insert node within the length of the linklist.
The second one is append a node at the end of the linklist.
We assume the length of the linklist is 10,the first one can insert nodes between 1 and 10.
For example, we insert nodes at the 10th place,then the 10th node change into 11.But the second is all the nodes can not change.We append a new node at the place of 11.

int insertList(linkList *L,int i,Elemtype data)
{
linklist p;
linklist insNode;
p = (*L);
int j=0;
// the linklist is empty,we insert a new node at the first place.
if(p->next == NULL){
printf(“the linklist is empty,we insert a new node at the first place.\n”);
insNode = (linkList)malloc(sizeif(Node));
insNode->data = data;
insNode->next = p->next;
p->next = insNode;
printf(“the node insert successfully.\n”);
return 1;
}
//at the situation of linklist is not empty.if beyand the length of the linkist,it will prompt error.
//
while(p&&j {
j++;
p = p-> next;
//printf(“j=%d\tp->data=%d\n”,j,p->data);
}
if(p->next == NULL){
printf(“the place you want to insert into has beyand the length of the linklist %d,please operate again!\n”,j);
return 0;
}
insNode = (linkList)malloc(sizeof(Node));
insNode->data = data;
insNode->next = p->next;
p->next = insNode;
printf(“the node has been inserted successfully\n”);
return 1;
}

Append node.
int insertListTail(linkList *L,ElemType data)
{
linkList temp;
linkList p=(*L);
while§
{
temp = p;
p = p->next;
}
p = (linkList)malloc(sizeof(Node));
p->data = data;
p->next = NULL;
temp->next = p;
printf(“the node has been inserted successfully\n”);
return 1;
}

(8) Delete nodes.
int deleteList(linkList *L,int i,ElemType *data)
{
linkList p,pnext;
int j = 0;
p = (*L);
if(p->next == NULL){
printf(“the linklist is empty,can not delete the node.\n”);
*data = -1;
return 0;
}
while(p->next && j j++;
p = p->next;
//printf(“j=%d\t p->data = %d\n”,j,p->data);
}
if( p -> next ==NULL) {
printf(“The node which you want to delete has beyond the length of linklist %d, please try again! \n”,j);
*data = -1;
return 0;
}
pnext = p->next;
p->next = pnext->next;
*data = pnext->data;
free(pnext);
printf(pnext);
printf(“the node has been deleted successfully\n”);
return 1;
}

(9) Delete this linkList.
int clearList(linkList *L){
linkList p,temp;
p = (*L)->next;
while§{
temp = p;
p = p->next;
free(temp);
}

   (*L)->next = NULL;
   printf("the whole linklist has been cleared.\n");
   return 1;
   }