双链表

来源：互联网发布：淘宝秒杀训练编辑：程序博客网时间：2024/06/07 20:15
#include <stdio.h>#include <stdlib.h>typedef struct dlink {int key;struct dlink *prev;struct dlink *next;}DLNode, *DLIST;DLNode *DListSearch(DLIST dl, int key){DLNode *p = dl;while (p != NULL && p->key != key) p = p->next;return p;}// 想办法优化一下DLIST DListInsert(DLIST dl, DLNode *x){DLNode *p = dl;if (p == NULL) { // Case 1:dl为空dl = x;return dl;}while (p->key < x->key && p->next != NULL)p = p->next;if (p->key < x->key && p->next == NULL) { // case 4:在dl最后插入x->next = p->next;x->prev = p;p->next = x;} else { x->next = p;x->prev = p->prev; if (p->prev == NULL) // case 2:在dl最前插入 dl = x;else                 // case 3:在dl中间插入p->prev->next = x;p->prev = x;}return dl;}DLIST DListDelete(DLIST dl, DLNode *x){if (dl == NULL) {printf("The doubly linked list is empty\n");return NULL;}if (x->prev != NULL) x->prev->next = x->next;else // 删除链表第一个元素dl = x->next;if (x->next != NULL)x->next->prev = x->prev;free(x);return dl;}void DListPrint(DLIST dl){DLNode *p = dl;while (p != NULL) {printf("%d\t", p->key);p = p->next;}printf("\n");}#ifndef NIL#define NIL 0#endif// A circular, doubly linked list with a sentinelDLIST CDListInit(){// 开辟一个哑结点作为哨兵DLNode *dl = (DLNode *)malloc(sizeof(DLNode));if (!dl) {printf("dl malloc error\n");return NULL;}dl->key = NIL;dl->prev = dl->next = dl;return dl;}DLNode *CDListSearch(DLIST dl, int key){DLNode *p = dl->next;while (p != dl && key != p->key)p = p->next;return p;}DLIST CDListInsert(DLIST dl, DLNode *x){DLNode *p = dl->next;// 在p后插入x// if (p == dl) { 可合并到下面的情况中去// x->next = p->next;// x->prev = p;// p->next->prev = x;// p->next = x;// } //else{while (p != dl && p->key < x->key)p = p->next;// 在p前插入xx->next = p;x->prev = p->prev;p->prev->next = x;p->prev = x;}return dl;}DLIST CDListDelete(DLIST dl, DLNode *x){x->prev->next = x->next;x->next->prev = x->prev;return dl;}void CDListPrint(DLIST dl){DLNode *p = dl->next;while (p != dl) {printf("%d\t", p->key);p = p->next;}printf("\n");}int main(){int arr[] = {34, 3, 223, 678, 1, 8, 43, 87, 1234};int len = sizeof(arr) / sizeof(arr[0]);DLIST dl = NULL;dl = CDListInit();printf("Insert:\n");for (int i = 0; i < len; i++) {DLNode *p = (DLNode *)malloc(sizeof(DLNode));if (!p) {printf("p malloc error\n");return -1;}p->key = arr[i];p->prev = p->next = NULL;dl = CDListInsert(dl, p);CDListPrint(dl);}printf("Delete:\n");for (int i = 0; i < len; i++) {dl = CDListDelete(dl, DListSearch(dl, arr[i]));CDListPrint(dl);}system("pause");return 0;}
0 0