数据结构练习（08）链表中倒数第k个结点

struct Node {
int key;
Node *next;
};

Node* findkth2tail(Node *head, unsigned int k)
{
if (head == NULL)
return NULL;

Node *p1, *p2;
p1 = head, p2 = NULL;

for (int i = 0; i < k; ++i)
{
if (p1->next != NULL)
p1 = p1->next;
else
return NULL;
}

p2 = head;

while (p1->next != NULL)
{
p1 = p1->next;
p2 = p2->next;
}

return p2;
}