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;

}