查找单链表的倒数第k个节点，要求只能遍历一次链表

源文件：

#include "LinkList.h"#include <assert.h>#include <stdio.h>// 在单链表的尾部插入一个节点void PushBack(PNode* pHead, DataType data){PNode pCurNode = NULL;PNode pNewNode = NULL;assert(pHead);    pNewNode = BuyNode(data);if(pNewNode == NULL)return;if(*pHead == NULL){*pHead = pNewNode;}else{pCurNode = *pHead;while(pCurNode->_pNext){pCurNode = pCurNode->_pNext;}pCurNode->_pNext = pNewNode;}}// 构建一个新节点Node* BuyNode(DataType data){PNode pNewNode = (Node*)malloc(sizeof(Node));if(pNewNode == NULL)return NULL;pNewNode->_data = data;pNewNode->_pNext = NULL;return pNewNode;}// 正向打印单链表void PrintList(PNode pHead){if(pHead == NULL)return;while(pHead){printf("%d->",pHead->_data);pHead = pHead->_pNext;}printf("NULL\n");}// 查找单链表的倒数第K个结点，要求只遍历一次链表PNode FindLastKNode(PNode pHead, size_t k){PNode pFastNode = NULL;PNode pSlowNode = NULL;if(pHead == NULL)return NULL;pSlowNode = pHead;pFastNode = pHead;while(--k){pFastNode = pFastNode->_pNext;if(pFastNode == NULL)return NULL;}while(pFastNode->_pNext){pSlowNode = pSlowNode->_pNext;pFastNode = pFastNode->_pNext;}return pSlowNode;}//销毁单链表，释放空间 void DestroyList(Node* pHead)   {      while(pHead)      {          Node* temp = pHead;  pHead = pHead->_pNext;          free(temp);      }  }  

测试文件：

#include "LinkList.h"void test(){PNode node = NULL;PushBack(&node,1);PushBack(&node,3);PushBack(&node,5);PushBack(&node,4);PushBack(&node,2);PushBack(&node,6);PrintList(node);node = FindLastKNode(node,3);printf("从倒数第k个结点开始的链表：\n");PrintList(node);DestroyList(node);}int main(){test();return 0;}