（链表）判断是否回文

4.判断是否回文
std::stack<Node*> st;

int len = GetLength(plist);Node* p = plist->next;
for (int i = 0; i < len / 2; i++)
{st.push(p);p = p->next;
}if (len % 2 != 0)p = p->next;while (p != NULL && !st.empty())
{if (p->data == st.top()->data){p = p->next;st.pop();}else{return false;}
}return true;