数据结构单链表

链表是一种物理存储单元上非连续、非顺序的存储结构，数据元素的逻辑顺序是通过链表中的指针链接次序实现的。

#include 
#include 
#include "SList.h"
#include 
#include 
PNode SListBuyNode(DateType date) {
	PNode node = (PNode)malloc(sizeof(SListNode));
	if (node == NULL) {
		assert(0);
		return NULL;
	}
	node->date = date;
	node->pNext = NULL;
	return node;
}


//链表初始化
void SListInit(PSList s) {
	assert(s);
	s->head = NULL;
}
//尾插
void SListPushBack(PSList s, DateType date) {
	assert(s);
	PNode newNode = SListBuyNode(date);
	if (s->head == NULL) {
		s->head = newNode;
	}
	else {
		PNode PCur = s->head;
		while (PCur->pNext) {
			PCur = PCur->pNext;
		}
		PCur->pNext = newNode;
	}
}

//头插
void SListPushFront(PSList s, DateType date) {
	assert(s);
	PNode newNode = SListBuyNode(date);
	newNode->pNext = s->head;
	s->head = newNode;
}


//尾删
void SListPopBack(PSList s) {
	assert(s);
	if (s->head == NULL) {
		return;
	}
	PNode PCur = s->head;
	PNode PPre = NULL;
	while (PCur->pNext) {
		PPre = PCur;
		PCur = PCur->pNext;
	}
	PPre->pNext = NULL;
	free(PCur);
}

//头删
void SListPopFront(PSList s) {
	assert(s);
	if (s->head == NULL) {
		return;
	}
	PNode PCur = s->head;
	s->head = s->head->pNext;
	free(PCur);
}

//pos位置后插入值为date的元素
void SListInsert(PNode pos, DateType date) {
	assert(pos);
	PNode newNode = SListBuyNode(date);
	newNode->pNext = pos->pNext;
	pos->pNext = newNode;
}

//删除pos位置的元素
void SListErase(PSList s, PNode pos) {
	assert(s);
	assert(pos);
	PNode PCur = s->head;
	PNode PPre = NULL;
	while (PCur) {
		if (PCur != pos) {
			PPre = PCur;
			PCur = PCur->pNext;
		}
		else {
			break;
		}
	}
	if (PPre != NULL) {
		PPre->pNext = pos->pNext;
	}
	else {
		s->head = pos->pNext;
	}
	free(pos);
}

//查找值为date的节点，找到返回地址，否则返回NULL
PNode SListFind(PSList s, DateType date) {
	assert(s);
	if (s->head == NULL) {
		return NULL;
	}
	PNode PCur = s->head;
	while (PCur) {
		if (PCur->date == date) {
			return PCur;
		}
		else {
			PCur = PCur->pNext;
		}
	}
	return NULL;
}

//获取链表中有效节点的个数
int SListSize(PSList s) {
	assert(s);
	int size = 0;
	PNode PCur = s->head;
	while (PCur) {
		++size;
		PCur = PCur->pNext;
	}
	return size;
}

//判空，空返回0，非空返回非0
int SListEmpty(PSList s) {
	assert(s);
	if (s->head == NULL) {
		return 0;
	}
	else {
		return 1;
	}
}

//清空链表
void SListClear(PSList s) {
	assert(s);
	PNode PCur = s->head;
	while (PCur) {
		PNode p = PCur;
		PCur = PCur->pNext;
		free(p);
	}
	s->head = NULL;
}

//销毁链表
void SListDestory(PSList s) {
	assert(s);
	PNode PCur = s->head;
	while (PCur) {
		free(PCur);
		PCur = PCur->pNext;
}