【数据结构】单链表

SList.h

#pragma once

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>


typedef int SLTDataType;

typedef struct SListNode
{
	SLTDataType data;
	struct SListNode* next;
}SLTNode;

void SLTPrint(SLTNode* phead);//打印

void SLTPushBack(SLTNode** pphead, SLTDataType x);//尾插
void SLTPushFront(SLTNode** pphead, SLTDataType x);//头插

void SLTPopBack(SLTNode** pphead);//尾删
void SLTPopFront(SLTNode** pphead);//头删

SLTNode* SLTFind(SLTNode* phead, SLTDataType x);//查找

void SLTInsert(SLTNode** pphead, SLTNode* pos, SLTDataType x);//pos前插入
void SLTErase(SLTNode** pphead, SLTNode* pos);//pos前删除
void SLTInsertAfter(SLTNode** pphead, SLTNode* pos, SLTDataType x);//pos后插入
void SLTEraseAfter(SLTNode** pphead, SLTNode* pos);//pos后删除

SList.c

#include "SList.h"

//打印
void SLTPrint(SLTNode* phead)
{
	SLTNode* cur = phead;
	while (cur != NULL)
	{
		printf("%d->", cur->data);
		cur = cur->next;
	}
	printf("NULL\n");
}

//寻找节点(新的链块）
SLTNode* BuySLTNode(SLTDataType x)
{
	SLTNode* newnode = (SLTNode*)malloc(sizeof(SLTNode));
	if (newnode == NULL)
	{
		perror("malloc fail");
		return NULL;
	}

	newnode->data = x;
	newnode->next = NULL;
}


//尾插
void SLTPushBack(SLTNode** pphead, SLTDataType x)
{
	assert(pphead);
	SLTNode* newnode = BuySLTNode(x);

	if (*pphead ==  NULL)
	{
		*pphead = newnode;
	}
	else 
	{
		//找尾
		SLTNode* tail = *pphead;
		while (tail->next != NULL)
		{
			tail = tail->next;
		}
		tail->next = newnode;
	}
}


//头插
void SLTPushFront(SLTNode** pphead, SLTDataType x)
{
	assert(pphead);
	SLTNode* newnode = BuySLTNode(x); 
	newnode->next = *pphead;
	*pphead = newnode;
}


//尾删
void SLTPopBack(SLTNode** pphead)
{
	//检查链表是否为空
	// 方法一
	//if (*pphead == NULL)
	//{
	//	return;
	//}
	//方法二
	assert(*pphead);

	if ((*pphead)->next == NULL)
	{
		free(*pphead);
		*pphead = NULL;
	}
	else
	{
		//找尾
		SLTNode* prev = NULL;
		SLTNode* tail = *pphead;
		while (tail->next != NULL)
		{
			prev = tail;
			tail = tail->next;
		}

		free(tail);
		tail = NULL;
		prev->next = NULL;
	}
}


//头删
void SLTPopFront(SLTNode** pphead)
{
	//检查链表是否为空
	// 方法一
	//if (*pphead == NULL)
	//{
	//	return;
	//}
	//方法二
	assert(pphead);
	assert(*pphead);

	SLTNode* first = *pphead;
	*pphead = first->next;
	free(first);
	first = NULL;
}


//搜索
SLTNode* SLTFind(SLTNode* phead, SLTDataType x)
{
	SLTNode* cur = phead;
	while (cur)
	{
		if (cur->data == x)
		{
			return cur;
		}
		cur = cur->next;
	}
	return NULL;
}


//在pos之前插入
void SLTInsert(SLTNode** pphead, SLTNode* pos, SLTDataType x)
{
	assert(pos);
	assert(pphead);

	if (pos == *pphead)
	{
		SLTPushFront(pphead, x);
	}
	else
	{
		SLTNode* prev = *pphead;
		while (prev->next != pos)
		{
			prev = prev->next;
		}

		SLTNode* newnode = BuySLTNode(x);
		prev->next = newnode;
		newnode->next = pos;
	}
}


//在pos位置删除
void SLTErase(SLTNode** pphead, SLTNode* pos)
{
	assert(pphead);
	assert(*pphead);
	assert(pos);

	if (*pphead == pos)
	{
		SLTPopFront(pphead);
	}
	else
	{
		//找到pos前一个位置
		SLTNode* prev = *pphead;
		while (prev->next != pos)
		{
			prev = prev->next;
		}
		prev->next = pos->next;
		free(pos);
		pos = NULL;
	}
}


//pos后插入
void SLTInsertAfter(SLTNode** pphead, SLTNode* pos, SLTDataType x)
{
	assert(pos);
	SLTNode* newnode= BuySLTNode(x);
	newnode->next = pos->next;
	pos->next = newnode;
}


//pos后删除
void SLTEraseAfter(SLTNode** pphead, SLTNode* pos)
{
	assert(pos);
	assert(pos->next);
	SLTNode* del = pos->next;
	pos->next = pos->next->next;
	free(del);
	del = NULL;
}

test.c 

#include"SList.h"

void TestSList1()
{
	SLTNode*plist = NULL;
	SLTPushBack(&plist, 1);
	SLTPushBack(&plist, 2);
	SLTPushBack(&plist, 3);
	SLTPushBack(&plist, 4);

	SLTPrint(plist);
}

void TestSList2()
{
	SLTNode* plist = NULL;
	SLTPushFront(&plist, 1);
	SLTPushFront(&plist, 2);
	SLTPushFront(&plist, 3);
	SLTPushFront(&plist, 4);

	SLTPrint(plist);

}

void TestSList3()
{
	SLTNode* plist = NULL;
	SLTPushFront(&plist, 1);
	SLTPushFront(&plist, 2);
	SLTPushFront(&plist, 3);
	SLTPushFront(&plist, 4);

	SLTPrint(plist);

	SLTPopFront(&plist);
	SLTPrint(plist);

	SLTPopFront(&plist);
	SLTPrint(plist);

	SLTPopFront(&plist);
	SLTPrint(plist);

	SLTPopFront(&plist);
	SLTPrint(plist);
}

void TestSList4()
{
	SLTNode* plist = NULL;
	SLTPushFront(&plist, 1);
	SLTPushFront(&plist, 2);
	SLTPushFront(&plist, 3);
	SLTPushFront(&plist, 4);

	SLTPrint(plist);

	SLTPopBack(&plist);
	SLTPrint(plist);
	SLTPopBack(&plist);
	SLTPrint(plist);
	SLTPopBack(&plist);
	SLTPrint(plist);
	SLTPopBack(&plist);
	SLTPrint(plist);
}

void TestSList5()
{
	SLTNode* plist = NULL;
	SLTPushFront(&plist, 1);
	SLTPushFront(&plist, 2);
	SLTPushFront(&plist, 3);
	SLTPushFront(&plist, 4);

	SLTPrint(plist);

	//值为2的那个节点
	SLTNode* ret = SLTFind(plist, 2);
	SLTInsert(&plist, ret, 15);
	SLTPrint(plist);
}

void TestSList6()
{
	SLTNode* plist = NULL;
	SLTPushFront(&plist, 1);
	SLTPushFront(&plist, 2);
	SLTPushFront(&plist, 3);
	SLTPushFront(&plist, 4);

	SLTPrint(plist);

	//值为2的那个节点
	SLTNode* ret = SLTFind(plist, 2);
	SLTErase(&plist,ret);
	ret = NULL;
	SLTPrint(plist);
}

int main()
{
	//TestSList1();
	//TestSList2();
	//TestSList3();
	//TestSList4();
	//TestSList5();
	TestSList6();

	return 0;
}