單鏈表中查找倒數第K個節點

// 查找鏈表的倒數第K個結點

示意圖：

PSListNode FindLastKNode(PSListNode pHead, int K )

{

                 PSListNode pFast = pHead ;

                 PSListNode pSlow = pHead ;

                 if (pHead == NULL || K <= 0)

                {

                                 return NULL ;

                }

                 while (--K )

                {

                                 if (pFast == NULL )

                                {

                                                 return NULL ;

                                }

                                pFast = pFast->pNext;

                }

                 while (pFast->pNext)

                {

                                pSlow = pSlow->pNext;

                                pFast = pFast->pNext;

                }

                 return pSlow;

}

建議：若是理解不清楚，必定要畫個圖，看着圖寫代碼會容易不少，思路也會清晰