【数据结构初阶】双链表

1.双链表的实现

1.1结口实现

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>typedef int LTDateType;
typedef struct ListNode
{struct ListNode* next;struct ListNode* prev;LTDateType date;
}LTNode;//创造结点
LTNode* BuyLTNode(LTDateType x);//初始化双链表
LTNode* LTInit();//打印双链表
void LTPrint(LTNode* phead);//尾插
void LTPushBack(LTNode* phead, LTDateType x);//尾删
void LTPopBack(LTNode* phead);//头插
void LTPushFront(LTNode* phead, LTDateType x);//头删
void LTPopFront(LTNode* phead);//计算
int LTSize(LTNode* phead);//查找
LTNode* LTFind(LTNode* phead, LTDateType x);//pos位置插入
void LTInsert(LTNode* pos, LTDateType x);//删除pos位置
void LTErase(LTNode* pos);//销毁双链表
void LTDestroy(LTNode* phead);

1.2申请结点

//创造结点
LTNode* BuyLTNode(LTDateType x)
{LTNode* node = (LTNode*)malloc(sizeof(LTNode));if (node == NULL){perror("malloc fail");exit(-1);}node->date = x;node->next = NULL;node->prev = NULL;return node;
}

1.3初始化双链表

//初始化双链表
LTNode* LTInit()
{LTNode* phead = BuyLTNode(0);phead->next = phead;phead->prev = phead;return phead;
}

1.4打印双链表

//打印双链表
void LTPrint(LTNode* phead)
{assert(phead);printf("phead<=>");LTNode* cur = phead->next;while (cur != phead){printf("%d<=>", cur->date);cur = cur->next;}printf("\n");
}

1.5尾插

//尾插
void LTPushBack(LTNode* phead, LTDateType x)
{assert(phead);LTNode* tail = phead->prev;LTNode* newnode = BuyLTNode(x);newnode->prev = tail;tail->next = newnode;newnode->next = phead;phead->prev = newnode;
}

1.6尾删

//尾删
void LTPopBack(LTNode* phead)
{assert(phead);assert(phead->next != phead);LTNode* tail = phead->prev;LTNode* tailPrev = tail->prev;free(tail);tailPrev->next = phead;phead->prev = tailPrev;
}

1.7头插

//头插
void LTPushFront(LTNode* phead, LTNode* x)
{assert(phead);LTNode* newnode = BuyLTNode(x);LTNode* first = phead->next;phead->next = newnode;newnode->prev = phead;newnode->next = first;first->prev = newnode;
}

1.8头删

//头删
void LTPopFront(LTNode* phead)
{assert(phead);assert(phead->next != phead);LTNode* first = phead->next;LTNode* second = first->next;free(first);phead->next = second;second->prev = phead;
}

1.9计算大小

//计算
int LTSize(LTNode* phead)
{assert(phead);int size = 0;LTNode* cur = phead->next;while (cur != phead){size++;cur = cur->next;}return size;
}

1.10查找

//查找
LTNode* LTFind(LTNode* phead, LTDateType x)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){if (cur->date == x)return cur;cur = cur->next;}return NULL;
}

1.11pos位置插入

//在pos位置插入
void LTInsert(LTNode* pos, LTDateType x)
{assert(pos);LTNode* posPrev = pos->prev;LTNode* newnode = BuyLTNode(x);posPrev->next = newnode;newnode->prev = posPrev;newnode->next = pos;pos->prev = newnode;
}

1.12删除pos位置

//删除pos位置
void LTErase(LTNode* pos)
{assert(pos);LTNode* posNext = pos->next;LTNode* posPrev = pos->prev;free(pos);posPrev->next = posNext;posNext->prev = posPrev;
}

1.12删除双链表

//销毁双链表
void LTDestroy(LTNode* phead)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){LTNode* next = cur->next;free(cur);cur = cur->next;}free(phead);
}

全部码源

List.h

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>typedef int LTDateType;
typedef struct ListNode
{struct ListNode* next;struct ListNode* prev;LTDateType date;
}LTNode;//创造结点
LTNode* BuyLTNode(LTDateType x);//初始化双链表
LTNode* LTInit();//打印双链表
void LTPrint(LTNode* phead);//尾插
void LTPushBack(LTNode* phead, LTDateType x);//尾删
void LTPopBack(LTNode* phead);//头插
void LTPushFront(LTNode* phead, LTDateType x);//头删
void LTPopFront(LTNode* phead);//计算
int LTSize(LTNode* phead);//查找
LTNode* LTFind(LTNode* phead, LTDateType x);//pos位置插入
void LTInsert(LTNode* pos, LTDateType x);//删除pos位置
void LTErase(LTNode* pos);//销毁双链表
void LTDestroy(LTNode* phead);

List.c

#include"List.h"//创造结点
LTNode* BuyLTNode(LTDateType x)
{LTNode* node = (LTNode*)malloc(sizeof(LTNode));if (node == NULL){perror("malloc fail");exit(-1);}node->date = x;node->next = NULL;node->prev = NULL;return node;
}//初始化双链表
LTNode* LTInit()
{LTNode* phead = BuyLTNode(0);phead->next = phead;phead->prev = phead;return phead;
}//打印双链表
void LTPrint(LTNode* phead)
{assert(phead);printf("phead<=>");LTNode* cur = phead->next;while (cur != phead){printf("%d<=>", cur->date);cur = cur->next;}printf("\n");
}//尾插
void LTPushBack(LTNode* phead, LTDateType x)
{assert(phead);LTNode* tail = phead->prev;LTNode* newnode = BuyLTNode(x);newnode->prev = tail;tail->next = newnode;newnode->next = phead;phead->prev = newnode;
}//尾删
void LTPopBack(LTNode* phead)
{assert(phead);assert(phead->next != phead);LTNode* tail = phead->prev;LTNode* tailPrev = tail->prev;free(tail);tailPrev->next = phead;phead->prev = tailPrev;
}//头插
void LTPushFront(LTNode* phead, LTNode* x)
{assert(phead);LTNode* newnode = BuyLTNode(x);LTNode* first = phead->next;phead->next = newnode;newnode->prev = phead;newnode->next = first;first->prev = newnode;
}//头删
void LTPopFront(LTNode* phead)
{assert(phead);assert(phead->next != phead);LTNode* first = phead->next;LTNode* second = first->next;free(first);phead->next = second;second->prev = phead;
}//计算
int LTSize(LTNode* phead)
{assert(phead);int size = 0;LTNode* cur = phead->next;while (cur != phead){size++;cur = cur->next;}return size;
}//查找
LTNode* LTFind(LTNode* phead, LTDateType x)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){if (cur->date == x)return cur;cur = cur->next;}return NULL;
}//在pos位置插入
void LTInsert(LTNode* pos, LTDateType x)
{assert(pos);LTNode* posPrev = pos->prev;LTNode* newnode = BuyLTNode(x);posPrev->next = newnode;newnode->prev = posPrev;newnode->next = pos;pos->prev = newnode;
}//删除pos位置
void LTErase(LTNode* pos)
{assert(pos);LTNode* posNext = pos->next;LTNode* posPrev = pos->prev;free(pos);posPrev->next = posNext;posNext->prev = posPrev;
}//销毁双链表
void LTDestroy(LTNode* phead)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){LTNode* next = cur->next;free(cur);cur = cur->next;}free(phead);
}

test.c

#include"List.h"void TestList1()
{LTNode* plist = LTInit();LTPushBack(plist, 1);LTPushBack(plist, 2);LTPushBack(plist, 3);LTPushBack(plist, 4);LTPushBack(plist, 5);LTPrint(plist);LTPopBack(plist);LTPrint(plist);LTPushFront(plist, 20);LTPrint(plist);
}void TestList2()
{LTNode* plist = LTInit();LTPushBack(plist, 1);LTPushBack(plist, 2);LTPushBack(plist, 3);LTPushBack(plist, 4);LTPushBack(plist, 5);LTPrint(plist);LTPopFront(plist);LTPrint(plist);LTSize(plist);
}void TestList3()
{LTNode* plist = LTInit();LTPushBack(plist, 1);LTPushBack(plist, 2);LTPushBack(plist, 3);LTPushBack(plist, 4);LTPushBack(plist, 5);LTPrint(plist);LTNode* pos = LTFind(plist, 3);LTInsert(pos, 20);LTPrint(plist);
}void TestList4()
{LTNode* plist = LTInit();LTPushBack(plist, 1);LTPushBack(plist, 2);LTPushBack(plist, 3);LTPushBack(plist, 4);LTPushBack(plist, 5);LTPrint(plist);LTNode* pos = LTFind(plist, 3);LTErase(pos);LTPrint(plist);
}int main()
{TestList4();return 0;
}

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