逆序打印单链表
逆序打印单链表有两种方法，分别是递归和非递归。
-----------------------------//递归实现逆序打印-----------------------------------
void PrintTailToHead(pList *pplist)
{
if (*pplist == NULL) //空链表
return;
if ((*pplist)->next == NULL) //链表只有一个节点
{
printf("%d\n", (*pplist)->data);
return;
}
PrintTailToHead((*pplist)->next);
printf("%d\n",(*pplist)->data);
}
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---------------------------------//非递归实现逆序打印---------------------------------
void PrintTailToHeadNor(pList *pplist)
{
pNode cur = NULL;
pNode tail = NULL;
cur = *pplist;
if (*pplist == NULL)
return;
if ((*pplist)->next == NULL)
{
printf("%d\n", (*pplist)->data);
return;
}
while (*pplist != tail)
{
cur = *pplist;
while (cur->next != tail)
{
cur = cur->next;
}
printf("%d->", cur->data);
tail = cur;
}
printf("NULL\n");
}
------------------------------------------------------------------------------------删除一个无头单链表的非尾节点
---------------------------------------------------------------------------------
void EraseNotTailNode(pNode pos)
{
pNode del = NULL;
if (pos == NULL || pos->next == NULL)
return;
del = pos->next;
pos->data = del->data;
pos->next = del->next;
free(del);
del = NULL;
}
---------------------------------------------------------------------------------在无头单链表的一个节点前插入一个节点(不能遍历链表)
----------------------------------------------------------------------------------
pNode BuyNode(DataType d)//创建新节点
{
pNode newNode = (pNode)malloc(sizeof(Node));
if (newNode == NULL)
{
perror("BuyNode : :malloc");
return NULL;
}
newNode->data = d;
newNode->next = NULL;
return newNode;
}
void InsertPosFrontNotTailNode(pNode pos, DataType x)
{
pNode newNode = NULL;
if (NULL == pos)
return;
newNode = BuyNode(pos->data);
newNode->next = pos->next;
pos->next = newNode;
pos->data = x;
}
----------------------------------------------------------------------------------查找链表的中间节点(只遍历一次)
该问题涉及到了快慢指针问题：分别定义一个快指针(走两步）和慢指针(走一步)，当快指针遍历完整个链表时，慢指针刚好指向链表中间节点，这样我们通过只遍历一次链表的方式得到链表中间节点。
------------------------------------------------------------------------------------
pNode FindMiddleNode(pNode pHead)//快慢指针问题
{
pNode Fast = pHead;
pNode Slow = pHead;//节点个数为奇数，查找到的是中间节点；节点个数为偶数，查找到的是后一个节点。
if (NULL == pHead)
return NULL;
while (Fast && Fast->next)
{
Fast = Fast->next->next;
Slow = Slow->next;
}
return Slow;
}
------------------------------------------------------------------------------------判断单链表是否带环
判断链表带环问题时，分别定义一个快指针(走两步）和慢指针(走一步)，如果两个指针最终相遇，即证明单链表带环。
----------------------------------------------------------------------------------
pNode HasListCircle(pNode pHead)
{
pNode Fast = pHead;
pNode Slow = pHead;
while (Fast && Fast->next)
{
Fast = Fast->next->next;
Slow = Slow->next;
if (Fast == Slow)
return Fast;
}
return NULL;
}
----------------------------------------------------------------------------------求带环链表的入口点
求解此问题首先得确定目标链表带环，且得求出相遇点。
----------------------------------------------------------------------------------
pNode EntryNodeListCircle(pNode pHead, pNode meet)
{
assert(pHead);
Node* cur = pHead;
Node* met = meet;
if (NULL == meet)
return 0;
while (cur != met)
{
cur = cur->next;
met = met->next;
}
return met;
}
----------------------------------------------------------------------------------求带环链表中环的长度
----------------------------------------------------------------------------------
int GetCircleLen(pNode meet)
{
int count = 1;
Node* cur = meet;
if (NULL == meet)
return 0;
while (cur->next != meet)
{
count++;
cur = cur->next;
}
return count;
}
----------------------------------------------------------------------------------查找单链表的倒数第K个节点
-----------------------------------------------------------------------------------
pNode FindLastKNode(pNode pHead, int k)
{
pNode Fast = pHead;
pNode Slow = pHead;
if (NULL == pHead || k <= 0)
return NULL;
while (k--)
{
if(NULL == Fast)
return NULL;
Fast = Fast->next;
}
while (Fast)
{
Fast = Fast->next;
Slow = Slow->next;
}
return Slow;
}
-----------------------------------------------------------------------------------单链表的逆置（不带环）
--------------------------------------------------------------------------------------
void Reverse_Link(pList *pplist)
{
pNode pre = NULL;
pNode cur = NULL;
pNode next = NULL;
assert(pplist!= NULL);
cur = *pplist;
while (cur)
{
next = cur->next;
cur->next = pre;
pre = cur;
cur = next;
}
*pplist = pre;
}
--------------------------------------------------------------------------------------冒泡排序单链表
----------------------------------------------------------------------------------
void BubbleSort(pNode pHead)
{
pNode TailNode = NULL;
if (NULL == pHead || NULL == pHead->next)
return;
while (TailNode != pHead)
{
pNode pre = pHead;
pNode cur = pre->next;
while (cur != TailNode)
{
if (pre->data > cur->data)
{
DataType tmp = pre->data;
pre->data = cur->data;
cur->data = tmp;
}
pre = cur;
cur = cur->next;
}
TailNode = pre;
}
}
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