//尾插法
bool ListInsert_back(LinkList*& L, LinkNode* node)
{
LinkNode* last = NULL;
if(!L || !node) return false;
//找到最后一个节点
last = L;
while (last->next) last = last->next;
//新的节点链接到尾部
node->next = NULL;
last->next = node;
return true;
}
last = L; while (last->next) last = last->next;

node->next = NULL; last->next = node;
