单向不带头链表的使用

链表的创建：

typedef struct LNode {SLDataType data;struct LNode* next;
}LNode,*LinkList;

按位查找

LNode* GetElem(LinkList L, int i) {int j = 1;LNode* p = L->next;if (i < 0)return NULL;if (i == 0)return L;while (p && j < i) {p = p->next;j++;}return p;
}

后插（将值为x的元素插入到第i个位置）

p=GetElen(L,i-1);
s->next=p->next;
p->next=s;

 前插操作

s->next=p->next;
p->next=s;
tmp=p->data;
p->data=s->data;
s->data=tmp;

 

 

按值查找

LNode* LocateElem(LinkList l, SLDataType e) {LNode* p = l->next;while (p && p->data != e) {p = p->next;}return p;
}

画图时应先画物理结构图在画逻辑结构图

链表的头插

//尾插
void SListPushBack(SLTNode** pphead, SLDataType x);

void SListPushBack(SLTNode** pphead, SLDataType x) {SLTNode* newnode = BuySListNode(x);if (*pphead == NULL) {*pphead = newnode;}else {//找尾结点的指针SLTNode* tail = *pphead;while (tail->next) {tail = tail->next;}//将尾结点链接到新的结点tail->next = newnode;}
}

链表的尾插

void SListPushFront(SLTNode** pphead, SLDataType x) {SLTNode* newnode = BuySListNode(x);newnode->next = *pphead;*pphead = newnode;
}

 链表的头删

//头删
void SListPopFront(SLTNode** pphead);

void SListPopFront(SLTNode** pphead)
{SLTNode* next = (*pphead)->next;free(*pphead);*pphead = next;
}

链表的尾删

//尾删
void SListPopBack(SLTNode** pphead);

void SListPopBack(SLTNode** pphead)
{//链表为空if (*pphead = NULL) {return;}//只有一个结点else if (*pphead) {free(*pphead);*pphead = NULL;}else {SLTNode* prev = NULL;SLTNode* tail = *pphead;while (tail->next) {prev = tail;tail = tail->next;}free(tail);prev->next = NULL;}}

 链表的结点查找

SLTNode* SListFind(SLTNode* phead, SLDataType x);

SLTNode* SListFind(SLTNode* phead, SLDataType x)
{SLTNode* cur=phead;while (cur) {if (cur->data == x) {return cur;}cur = cur->next;}return NULL;
}

结点的创建

SLTNode* BuySListNode(SLDataType x) {SLTNode* newnode = (SLTNode*)malloc(sizeof(SLTNode));newnode->data = x;newnode->next = NULL;return newnode;
}

在pos的前面插入x 

//在pos的前面插入x
void SListInsert(SLTNode** pphead,SLTNode* pos, SLDataType x);

void SListInsert(SLTNode** pphead, SLTNode* pos, SLDataType x) {if (pos == *pphead) {SListPushFront(pphead, x);}else {SLTNode* newnode = BuySListNode(x);SLTNode* prev = *pphead;while (prev->next != pos) {prev = prev->next;}prev->next = newnode;newnode->next = pos;}
}

删除pos位置的值

void SListErase(SLTNode** pphead, SLTNode* pos) {if (pos = *pphead) {SListPopFront(pphead);}else {SLTNode* prev = *pphead;while (prev->next != pos) {prev = prev->next;}prev->next = pos->next;free(pos);}}