双向链表的简单操作

data.h

#ifndef _DATA_H_#define _DATA_H_typedef struct DbNode{int data;struct DbNode *left;struct DbNode *right;}DbNode;#endif

 

doubleLinklist.h

#ifndef DOUBLE_LINKLIST_H#define DOUBLE_LINKLIST_H#include "data.h"#include <stdlib.h>#include <stdio.h>DbNode* CreateNode(int data){DbNode *pnode = (DbNode*)malloc(sizeof(DbNode));pnode->data = data;pnode->left= pnode->right = NULL;#ifdef DEBUGprintf("%s data = %d\n",__FUNCTION__,data);#endifreturn pnode;}DbNode* CreateList(int head){DbNode *pnode = (DbNode*)malloc(sizeof(DbNode));pnode->data = head;pnode->left= pnode->right = NULL;#ifdef DEBUGprintf("%s head = %d\n",__FUNCTION__,head);#endifreturn pnode;}DbNode* AppendNode(DbNode* head,int data){DbNode* node = CreateNode(data);DbNode* p = head;DbNode* q;while(p != NULL){q = p;p = p->right;}q->right = node;node->left = q;#ifdef DEBUGprintf("%s data = %d\n",__FUNCTION__,data);#endifreturn head;}int GetLength(DbNode* head){int count = 1;DbNode* pnode = NULL;if(head == NULL)return 0;pnode = head->right;while(pnode != NULL){pnode = pnode->right;count++;}return count;}void PrintList(DbNode* head){DbNode* pnode = NULL;if(head == NULL)return;pnode = head;printf("Double list show as below\n");while(pnode != NULL){printf("%d ",pnode->data);pnode = pnode->right;}printf("\n");}int FindNode(DbNode* head,int find_this_data){int pos = 0;DbNode* pnode = head;if(head == NULL)return -1;while(pnode->right != NULL && pnode->data != find_this_data){pnode = pnode->right;pos++;}/* * There is no this specific number * */if(pnode->right == NULL && pnode->data != find_this_data)return -2;return pos + 1;}DbNode* FindNode2(DbNode* head,int data){DbNode* pnode = head;/* * 链表为空 * */if(head == NULL)return NULL;/* * 找到数据或者到达链表尾部就退出while循环 * */while(pnode->right != NULL && pnode->data != data)pnode = pnode->right;/* * 没有找到数据为data的结点 * */if(pnode->right == NULL && pnode->data != data)return NULL;return pnode;}void InsertNode(DbNode* head,int insert_after_this_pos,int insert_this_data){/* * 如果头结点为空，什么都不操作 * */DbNode* newNode = CreateNode(insert_this_data);int len;if(head == NULL)return;elselen = GetLength(head);if(len < insert_after_this_pos){printf("Insert out of range\n");return;}DbNode* pnode = head;int tmpPos = 0;while(pnode->right != NULL && tmpPos < insert_after_this_pos - 1){pnode = pnode->right;tmpPos++;}/* * 如果pnode是最后一个结点 * */if(pnode->right == NULL){pnode->right = newNode;newNode->left = pnode;}else//是中间的结点{/* * 新结点的right指向pnode结点的下一个结点 * */newNode->right = pnode->right;/* * pnode的下一个结点的left指向newNode * */pnode->right->left = newNode;/* * pnode的right指向newNode * */pnode->right = newNode;/* * newNode的left指向pnode * */newNode->left = pnode;}}DbNode* DeleteNode(DbNode* head,int del_this_data){DbNode* ptmp = NULL;DbNode* pnode = FindNode2(head,del_this_data);/* * 要删除的结点不存在,返回head不做任何操作 * */if(pnode == NULL){printf("There is no %d in the linklist\n",del_this_data);return head;}/* *要删除的结点是第一个结点 * */else if(pnode->left == NULL){/* * 让第二个结点作为头结点 * */head = pnode->right;/* * 链表不为空 * */if(head != NULL)head->left = NULL;}/* *要删除的结点是最后一个结点 *让倒数第二个结点的right指向null * */else if(pnode->right == NULL)pnode->left->right = NULL;/* * 要删除的结点是中间的结点 * */else{/* * pnode结点的上一个结点的right指向pnode的下一个结点 * */pnode->left->right = pnode->right;/* * pnode的下一个结点的left指向pnode的上一个结点 * */pnode->right->left = pnode->left;}free(pnode);return head;}#endif

main.c

#include "doubleLinklist.h"int main(){DbNode* head = CreateList(0);int i;for(i = 1; i < 9; i++)head = AppendNode(head,i);PrintList(head);int len = GetLength(head);printf("len(linklist) = %d\n",len);printf("Find:");int find;scanf("%d",&find);int res = FindNode(head,find);if(res < 0)printf("No this data\n");elseprintf("Data pos = %d\n",res);printf("InsertPos[0,len] & data:");int insertPos,insertData;scanf("%d,%d",&insertPos,&insertData);InsertNode(head,insertPos,insertData);printf("Insert %d after pos %d\n",insertData,insertPos - 1);PrintList(head);int del;printf("Delete data:");scanf("%d",&del);head = DeleteNode(head,del);printf("Delete %d from linklist!!!\n",del);PrintList(head);return 0;}