双向链表

来源：互联网发布：四宫格拍照软件是什么编辑：程序博客网时间：2024/06/06 20:11
解释，我们在单链表中，有了next指针，查找下一元素为O（1），而查找上一节点的话，则是O（n）。
所以为了克服单向性这一缺点，我们在单链表的每个节点中，在设置一个指向其前区节点的指针域。
#include "string.h"#include "ctype.h"#include "stdio.h"#include "stdlib.h"#include "io.h"#include "math.h"#include "time.h"#define OK 1#define ERROR 0#define TRUE 1#define FALSE 0#define MAXSIZE 1000 /* 存储空间初始分配量 */typedef int ElemType ;typedef int status  ;typedef struct DulNode{    ElemType data;    struct DulNode * next;    struct DulNode * prior;}DulNode,*DuLinkList;//typedef struct DulNode* DuLinkList; 和上述表示方法一样status InitList(DuLinkList * L){ (*L) =(DuLinkList) malloc(sizeof(DulNode));    if(*L == NULL){        return ERROR;    }else{        (*L)->next = NULL;        (*L)->prior = NULL;        return OK;    }}status EemptyList(DuLinkList L){    if(L->next == NULL){        return ERROR;    }else{        return OK;    }}status Inserthead(DuLinkList **L,ElemType e){    DuLinkList first;    first = (DuLinkList)malloc(sizeof(DulNode));    first->data = e;    //printf("%p\n",(*(*L)));    (*(*L))->next = first;    first->prior = (*(*L));    first->next = NULL;    return -1;}status InsertTail(DuLinkList *L,ElemType e){//从表尾插 //    DuLinkList rear;    rear = (DuLinkList)malloc(sizeof(DulNode));    rear->data = e;    (*L)->next = rear;    rear->prior = (*L);    rear->next = NULL;return 1;}status ListInsert(DuLinkList *L , int i, ElemType e){//考虑没有节点和插入到第一个位置    if(!EemptyList(*L))       return Inserthead(&L,e);    DuLinkList p = (*L);    int j=1;    while(p && j<i ){        p = p->next;        j++;    }    if(!p||j>i){//用于判断i大于公共的节点数越界的情况和i=0的情况        return ERROR;    }    if(p->next == NULL){//最后一个位置的后一个位置       InsertTail(&p,e); //传p不用重新遍历       return -1;    }    DuLinkList q = (DuLinkList)malloc(sizeof(DulNode));    q->data = e;    q->next = p->next;    q->prior=p;    p->next->prior = q;    p->next = q;}status GetElem(DuLinkList L ,int i , ElemType *e){  //L指向头结点 L叫头指针    int j=1;    DuLinkList p = L->next;//指向第一个节点    while(p&&j<i){      j++;      p = p->next;    }    if(!p||j>i){      return ERROR;    }    *e = p->data;    return OK;}status DeleteList(DuLinkList * L , int i ,ElemType *e){//由于是双向链表没有必要再去找到i-1个位置    if(!EemptyList(*L))    return ERROR;    int j=1;    DuLinkList p = (*L)->next; //从第一个位置开始    while(p&&j<i){        j++;        p=p->next;    }    if(!p||j<i){        printf("dasdasd\n");        return ERROR;    }    *e = p->data;    if(p->next==NULL){ //删除最后一个元素        p->prior->next = NULL;        free(p);        return OK;    }    p->prior->next = p->next;    p->next->prior = p->prior;    free(p);    return OK;}int ListLength(DuLinkList L){    if(!EemptyList(L))    return 0;    int j=0;    DuLinkList p = L->next;    while(p){        j++;        p = p->next;    }return j;}status FromHeadInsert(DuLinkList *L ,int n){    (*L) =(DuLinkList) malloc(sizeof(DulNode));    (*L)->next  = NULL;    (*L)->prior = NULL;    int i;    srand(time(0));    DuLinkList q=NULL;//用于记录原第一个节点的位置    for(i=0;i<n;i++){        DuLinkList s;        s = (DuLinkList) malloc(sizeof(DulNode));        s->data = rand()%100+1;        s->prior = (*L);        s->next = q;        if(i!=0)        (*L)->next->prior = s;//除了第一次插入的节点外，以后每次插                             //入都需要设置原来的节点的前一个指向新的节点        //q->prior = s 也可以        (*L)->next = s;        q=s;    }return OK;}status FromTailInsert(DuLinkList *L ,int n){    (*L) =(DuLinkList) malloc(sizeof(DulNode));    (*L)->next  = NULL;    (*L)->prior = NULL;    int i;    srand(time(0));    DuLinkList q=(*L);//用于记录原节点的位置     for(i=0;i<n;i++){        DuLinkList s;        s = (DuLinkList) malloc(sizeof(DulNode));        s->data = rand()%100+1;        s->prior = q;        s->next = NULL;        q->next = s;        q=s;    }}status ClearList(DuLinkList *L){    if(!EemptyList(*L))    return ERROR;    DuLinkList p=(*L)->next,q;    while(p){      q=p->next;      free(p);      p=q;    }    (*L)->next  = NULL;    (*L)->prior = NULL;    return OK;}int LocateElem(DuLinkList L,ElemType e){    if(!EemptyList(L))    return ERROR;    DuLinkList p=L->next;    int i=1;    while(p){        if(p->data == e)        {          return i;        }        p=p->next;        i++;    }    return ERROR;}int main(){    DuLinkList node;    InitList(&node);    //判读是否为空    printf("%d\n",EemptyList(node));    ListInsert(&node,1,2);//从头插    printf("%p\n",node);   // printf("%d\n",node->next->data);    ListInsert(&node,1,5);    ListInsert(&node,2,7);    ListInsert(&node,2,9);    ListInsert(&node,5,19);//插入到最后一个位置的下一个    DuLinkList first,first1;    first = node->next;     while(first){        printf("%d\n",first->data);        first1 = first;        first= first->next;    }     printf("\n");     while(first1!=node){        printf("%d\n",first1->data);        first1= first1->prior;    }    printf("\n");//得到元素int value;GetElem(node,5,&value);printf("%d\n",value);//删除元素printf("\n");printf("%d\n",DeleteList(&node,1,&value));//printf("%d\n",value);first = node->next;     while(first){        printf("%d\n",first->data);        first1 = first;        first= first->next;    }    printf("\n");     while(first1!=node){        printf("%d\n",first1->data);        first1= first1->prior;    }printf("\n");//计算长度int chang = ListLength(node);printf("%d\n",chang);//头插法printf("\n");DuLinkList HeadInsert,test,test1;FromHeadInsert(&HeadInsert,10);test = HeadInsert->next;     while(test){        printf("%d\n",test->data);        test1 = test;        test= test->next;    }   printf("\n");    while(test1!=HeadInsert){        printf("%d\n",test1->data);        test1= test1->prior;    }printf("\n");//尾插法DuLinkList TailInsert;FromTailInsert(&TailInsert,3);test = TailInsert->next;     while(test){        printf("%d\n",test->data);        test1 = test;        test= test->next;    }   printf("\n");    while(test1!=TailInsert){        printf("%d\n",test1->data);        test1= test1->prior;    }      printf("\n");//清空链表printf("%p\n",TailInsert);ClearList(&TailInsert);printf("%p\n",TailInsert);//查找相等元素的位置int result = LocateElem(node,19);printf("%d\n",result);return 0;}
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