C语言--单链表的所有操作实现

单链表的所有操作实现

// 动态申请一个节点
SListNode* BuySListNode(SLTDateType x)

//链表初始化
void SListInit(Head* plist)

// 单链表打印
void SListPrint(Head* plist)

// 单链表尾插
void SListPushBack(Head* pplist, SLTDateType x)

// 单链表的头插
void SListPushFront(Head* pplist, SLTDateType x)

// 单链表的尾删
void SListPopBack(Head* pplist)

// 单链表头删
void SListPopFront(Head* pplist)

// 单链表查找
SListNode* SListFind(Head* plist, SLTDateType x)

// 单链表在pos位置之后插入x
void SListInsertAfter(SListNode* pos, SLTDateType x)

// 单链表删除pos位置之后的值
void SListEraseAfter(SListNode* pos)

//释放链表所有空间
void SListDestory(Head* plist)

#include<stdio.h>
#include<stdlib.h>
//无头单向不循环链表

typedef int SLTDateType;
typedef struct SListNode
{
 SLTDateType data;
 struct SListNode* next;
}SListNode;

typedef struct Head
{
 struct SListNode* head;  //链表第一个有效元素的位置
}Head;

// 动态申请一个节点
SListNode* BuySListNode(SLTDateType x) {
 SListNode* node = (SListNode*)malloc(sizeof(SListNode));
 node->data = x;
 node->next = NULL;
 return node;
}

//链表初始化
void SListInit(Head* plist) {
 plist->head = NULL;
}

// 单链表打印
void SListPrint(Head* plist) {
 SListNode* cur = plist->head;
 while (cur) {
  printf("%d ", cur->data);
  cur = cur->next;
 }
 }
 
 // 单链表尾插
void SListPushBack(Head* pplist, SLTDateType x) {
 SListNode* node = BuySListNode(x);
 if (pplist == NULL) {
  pplist->head = node;
 }
 else {
  SListNode* cur = pplist->head;
  while (cur->next) {  //找到最后一个元素
   cur = cur->next;
  }
  cur->next = node;
 }
}

// 单链表的头插
void SListPushFront(Head* pplist, SLTDateType x) {
 SListNode* node = BuySListNode(x);
 //判断是否为空表
 if (pplist == NULL) {
  pplist->head = node;
  }
 else {
  node->next = pplist->head;
  pplist->head = node;
 }
}

// 单链表的尾删
void SListPopBack(Head* pplist) {
 //判断是否非空链表
 if (pplist->head) {
  SListNode* cur = NULL;  //最后一个节点的前一个节点
  SListNode* last = pplist->head;   //最后一个节点
  while (last->next) {
   cur = last;
   last = last->next;
  }
  //在判断删除掉的是不是头节点，即链表是不是只有一个元素
  if (last == pplist->head) {
   pplist->head = NULL;
  }
  else {
   cur->next = NULL;
  }
  free(last);
 }
}

// 单链表头删
void SListPopFront(Head* pplist) {
 if (pplist->head) {
  SListNode* cur = pplist->head;  //指向第一个元素
  pplist->head = cur->next;
  free(cur);
 }
}

/*
//头删的另外一种操作，传二级指针，其他增删改也可采用这种二级指针方式
void SListPopFront(SListNode** pplist) {
 if (*pplist) {
  SListNode* new = (*pplist)->next;
  free(*pplist);
  *pplist = new;
 }
}
*/

// 单链表查找
SListNode* SListFind(Head* plist, SLTDateType x) {
 SListNode* cur = plist->head;
 while (cur) {
  if (cur->data == x) {
   return cur;
  }
  cur = cur->next;
 }
 return NULL;
}

// 单链表在pos位置之后插入x
void SListInsertAfter(SListNode* pos, SLTDateType x) {
 SListNode* node = BuySListNode(x);
 node->next = pos->next;
 pos->next = node;
}

// 单链表删除pos位置之后的值
void SListEraseAfter(SListNode* pos) {
 SListNode* next;
 if (pos == NULL){
  return;
 }
 next = pos->next;
 if (next) {
  pos->next = next->next;
  free(next);
 }
}

//释放链表所有空间
void SListDestory(Head* plist) {
 SListNode* cur = plist->head;
 while (cur) {
  SListNode* next = cur->next;
  free(cur);
  cur = next;
 }
}

int main() {
 Head plist;
 SListInit(&plist);
 SListPushFront(&plist, 1);
 SListPushFront(&plist, 2);
 SListPushFront(&plist, 3);
 SListPushFront(&plist, 4);
 SListPushFront(&plist, 5);
 SListPrint(&plist);    //头插5个
 printf("\n");
 
 SListPushBack(&plist, 100);
 SListPushBack(&plist, 200);
 SListPushBack(&plist, 300);
 SListPrint(&plist);   //尾插3个
 printf("\n");

SListPopBack(&plist);
 SListPrint(&plist);   //尾删1个
 printf("\n");
 
SListPopFront(&plist);
 SListPopFront(&plist);
 SListPrint(&plist);   //头删2个
 printf("\n");
 
 SListNode* pos = SListFind(&plist, 2);
 SListInsertAfter(pos, 666);   //在2后边插入666
 SListPrint(&plist);
 printf("\n");
 
 SListNode* pos1 = SListFind(&plist, 3);
 SListEraseAfter(pos1);        //删除3后边的一个元素
 SListPrint(&plist);
 printf("\n");
 return 0;
}