循环链表的学习

循环链表最合适的一个场景就是约瑟夫问题

#ifndef _CIRCLELIST_H_#define _CIRCLELIST_H_typedef void CircleList;/*typedef struct _tag_CircleListNode CircleListNode;struct _tag_CircleListNode{CircleListNode* next;};*/typedef struct _tag_CircleListNode{struct _tag_CircleListNode * next;}CircleListNode;CircleList* CircleList_Create();void CircleList_Destroy(CircleList* list);void CircleList_Clear(CircleList* list);int CircleList_Length(CircleList* list);int CircleList_Insert(CircleList* list, CircleListNode* node, int pos);CircleListNode* CircleList_Get(CircleList* list, int pos);CircleListNode* CircleList_Delete(CircleList* list, int pos);//addCircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node);CircleListNode* CircleList_Reset(CircleList* list);CircleListNode* CircleList_Current(CircleList* list);CircleListNode* CircleList_Next(CircleList* list);#endif

#include <stdio.h>#include <malloc.h>#include "CircleList.h"typedef struct _tag_CircleList{CircleListNode header;CircleListNode* slider;int length;} TCircleList;CircleList* CircleList_Create() // O(1){TCircleList* ret = (TCircleList*)malloc(sizeof(TCircleList));if (ret == NULL){return NULL;}ret->length = 0;ret->header.next = NULL;ret->slider = NULL;return ret;}void CircleList_Destroy(CircleList* list) // O(1){if (list == NULL){return ;}free(list);}void CircleList_Clear(CircleList* list) // O(1){TCircleList* sList = (TCircleList*)list;if (sList == NULL){return ;}sList->length = 0;sList->header.next = NULL;sList->slider = NULL;}int CircleList_Length(CircleList* list) // O(1){TCircleList* sList = (TCircleList*)list;int ret = -1;if (list == NULL){return ret;}ret = sList->length;return ret;}int CircleList_Insert(CircleList* list, CircleListNode* node, int pos) // O(n){ int ret = 0, i=0;TCircleList* sList = (TCircleList*)list;if (list == NULL || node== NULL || pos<0){return -1;}//if( ret ){CircleListNode* current = (CircleListNode*)sList;for(i=0; (i<pos) && (current->next != NULL); i++){current = current->next;}//current->next 0号节点的地址node->next = current->next; //1current->next = node; //2//若第一次插入节点if( sList->length == 0 ){sList->slider = node;}sList->length++;//若头插法if( current == (CircleListNode*)sList ){//获取最后一个元素CircleListNode* last = CircleList_Get(sList, sList->length - 1); last->next = current->next; //3}}return ret;}CircleListNode* CircleList_Get(CircleList* list, int pos) // O(n){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;int i = 0;if (list==NULL || pos<0){return NULL;}//if( (sList != NULL) && (pos >= 0) && (sList->length > 0) ){CircleListNode* current = (CircleListNode*)sList;for(i=0; i<pos; i++){current = current->next;}ret = current->next;}return ret;}CircleListNode* CircleList_Delete(CircleList* list, int pos) // O(n){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;int i = 0;if( (sList != NULL) && (pos >= 0) && (sList->length > 0) ){CircleListNode* current = (CircleListNode*)sList;CircleListNode* last = NULL;for(i=0; i<pos; i++){current = current->next;}//若删除第一个元素if( current == (CircleListNode*)sList ){last = (CircleListNode*)CircleList_Get(sList, sList->length - 1);}//求要删除的元素ret = current->next;current->next = ret->next;sList->length--;//判断链表是否为空if( last != NULL ){sList->header.next = ret->next;last->next = ret->next;}//若删除的元素为游标所指的元素if( sList->slider == ret ){sList->slider = ret->next;}//若删除元素后，链表长度为0if( sList->length == 0 ){sList->header.next = NULL;sList->slider = NULL;}}return ret;}CircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node) // O(n){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;int i = 0;if( sList != NULL ){CircleListNode* current = (CircleListNode*)sList;//查找node在循环链表中的位置ifor(i=0; i<sList->length; i++){if( current->next == node ){ret = current->next;break;}current = current->next;}//如果ret找到，根据i去删除if( ret != NULL ){CircleList_Delete(sList, i);}}return ret;}CircleListNode* CircleList_Reset(CircleList* list) // O(1){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;if( sList != NULL ){sList->slider = sList->header.next;ret = sList->slider;}return ret;}CircleListNode* CircleList_Current(CircleList* list) // O(1){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;if( sList != NULL ){ret = sList->slider;}return ret;}CircleListNode* CircleList_Next(CircleList* list) // O(1){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;if( (sList != NULL) && (sList->slider != NULL) ){ret = sList->slider;sList->slider = ret->next;}return ret;}

#include <stdio.h>#include <stdlib.h>#include "CircleList.h"struct Value{CircleListNode header;int v;};void  main(){int i = 0;CircleList* list = CircleList_Create();struct Value v1, v2, v3, v4, v5, v6, v7, v8;v1.v = 1;v2.v = 2;v3.v = 3;v4.v = 4;v5.v = 5;v6.v = 6;v7.v = 7;v8.v = 8;CircleList_Insert(list, (CircleListNode*)&v1, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v2, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v3, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v4, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v5, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v6, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v7, CircleList_Length(list));CircleList_Insert(list, (CircleListNode*)&v8, CircleList_Length(list));for(i=0; i<CircleList_Length(list); i++){struct Value* pv = (struct Value*)CircleList_Next(list);printf("%d\n", pv->v);}printf("\n");//重置游标CircleList_Reset(list);while( CircleList_Length(list) > 0 ){struct Value* pv = NULL;for(i=1; i<3; i++){CircleList_Next(list);}pv = (struct Value*)CircleList_Current(list);printf("%d\n", pv->v);CircleList_DeleteNode(list, (CircleListNode*)pv);}CircleList_Destroy(list);system("pause");return ;}