链表中倒数第k个结点

代码：

struct ListNode{    int m_nValue;    ListNode* m_pNext;};ListNode* findKthtoTail(ListNode* pHead, int k){    if (pHead == nullptr || k <= 0)        return nullptr;    ListNode *p1 = pHead, *p2 = pHead;    for (int i = 1; i < k; k++)    {        if (p1->m_pNext == nullptr) //若节点少于k个            return nullptr;        p1 = p1->m_pNext;    }    while (p1->m_pNext != nullptr)    {        p2 = p2->m_pNext;        p1 = p1->m_pNext;    }    return p2;}