关于链表中是否带环和找到环的入口点

面试题一：判断链表是否带环

<span style="font-size:18px;"><strong style="background-color: rgb(255, 255, 255);">int FndLoop(pLinkList list)
{
pLinkNode fast=list->pHead;
pLinkNode slow=list->pHead;
assert(list);
while(fast!=NULL && fast->next!=NULL)
{
slow=slow->next;
fast=fast->next->next;
if( fast!=NULL && slow==fast)
{
return 1;//有环
}
}
return 0;//无环
}</strong></span>
面试题二：找到环的入口点


<span style="font-size:18px;"><strong>pLinkNode FndLoopNode(pLinkList list)
{
pLinkNode fast=list->pHead;
pLinkNode slow=list->pHead;
assert(list);
while(fast!=NULL && fast->next!=NULL)
{
slow=slow->next;
fast=fast->next->next;
if( fast!=NULL && slow==fast)
{
break;
}
}
slow=list->pHead;
while(slow!=fast)
{
slow=slow->next;
fast=fast->next;
}
return slow;
}</strong></span>