C链表实现（单向，双向）

一、单向链表

#include <stdio.h>
#include <stdlib.h>
#define FALSE 0
#define TRUE  1
//#include "link.h"
typedef struct NODE
{
        struct NODE *link;
        int          value;
}Node;
//createNode()
Node * createNode(int value)
{
     Node *node;
     node = (Node*)malloc(sizeof(Node));
     if(node!=NULL)
     {
         node->value = value;
         node->link = NULL;   
     }
     else
     {
        printf("Not Enough Memory!\n"); 
     }
}
//sortinsert()
int sortInsert(register Node**linkp,int new_value)
{
 		register Node *current;
 		register Node *new;
 		
 		while((current = *linkp)!=NULL && current->value<new_value)
		   linkp = &current->link;
   
    new = (Node*)malloc(sizeof(Node));
    if(new == NULL)
       return FALSE;
    new->value = new_value;
    new->link = current;
    *linkp = new ;
    return TRUE;
}
//freeLinkList()
void freeLinkList(Node * head)
{ 
    if(head == NULL) 
    { 
        printf("\n Empty memory! \n"); 
        return; 
    } 
    Node *ptr = head;
    Node * curr;
    while(ptr->link != NULL)
    {
        curr = ptr;
        ptr = ptr->link;
        free(curr);  
    }
    free(ptr);
}
//printLinkList()
void printLinkList(Node * head)
{
     if(head == NULL) 
         return;
     while(head->link != NULL)
     {
         head = head->link;
         printf("%d -> ",head->value);
     }
     putchar('\n');
}
//main()
int main(int argc, char *argv[])
{
  Node * head;
  head = (Node*)malloc(sizeof(Node));
  int i;
  for(i=0;i<10;i++)
  {
          Node * newNode = createNode(i);
          newNode->link = head->link;
          head->link = newNode;
  }
  printLinkList(head);
  sortInsert(&head->link,13);
  sortInsert(&head->link,10);
  printLinkList(head);
  
  freeLinkList(head);
  system("PAUSE");	
  return 0;
}

 

二、双向链表

#include<stdio.h>
#include<stdlib.h>
#define FALSE 0
#define TRUE  1

typedef struct NODE
{
 				struct NODE *fwd;
 				struct NODE *bwd;
 				int         value;
}Node;
//插入节点 
int dll_insert(register Node * rootp,int value)
{
 		register Node * this;
 		register Node * next;
 		register Node * newnode;
 		
 		for(this =rootp;(next = this->fwd)!=NULL;this = next)
 		{
		 				 if(next->value == value)
								return FALSE;
			       if(next->value > value)
								break;
    }
    
    newnode = (Node*)malloc(sizeof(Node));
    if(newnode == NULL)
      return -1;
    newnode->value = value;
    /*插入新节点*/
    newnode->fwd = next;
    this->fwd =newnode;
    newnode->bwd = this != rootp ? this : NULL;
    (next != NULL ? next:rootp)->bwd = newnode;	
 		return 1;
}
//打印链表 
void printLinklist(Node * rootp)
{
 		 if(rootp == NULL)
				return;
     Node * temp = rootp;
     while(temp->fwd != NULL)
     {
				temp = temp->fwd;
				printf("%d->",temp->value);
		 }
		 printf("NULL\n");
}
//释放链表空间 
void freeLinkList(Node * rootp)
{ 
    if(rootp == NULL) 
    { 
        printf("\n Empty memory! \n"); 
        return; 
    } 
    Node *ptr = rootp;
    Node * curr;
    while(ptr->fwd != NULL)
    {
        curr = ptr;
        ptr = ptr->fwd;
        free(curr);  
    }
    free(ptr);
}
//main
int main(int argc, char *argv[])
{
 		Node * rootp;
 		rootp = (Node*)malloc(sizeof(Node));
 		rootp->bwd = NULL;
 		rootp->fwd = NULL;
 		int i;
 		for(i=0;i<10;i++)
 		{
        dll_insert(rootp,i);
 		}
 		printLinklist(rootp);
 		freeLinkList(rootp);
    system("PAUSE");	
    return 0;
}