查找单链表的倒数第N个节点

查找单链表的倒数第N个节点(C语言)

LinkedList* GetNthNodeFromBack(LinkedList* Head, int N)

{

int i = 0;

LinkedList* firstNode = Head;

while (i < N && firstNode->next != NULL)

{ //正数N个节点，firstNode指向正的第N个节点

i++;

firstNode = firstNode->next;

}

if (firstNode->next == NULL && i < N - 1)

{ //当节点数量少于N个时，返回NULL

return NULL;

}

LinkedList* secNode = Head;

while (firstNode->next != NULL)

{ //查找倒数第N个元素

secNode = secNode->next;

firstNode = firstNode->next;

}

return secNode;

}