0001 #define npl height //假借高度，用作NPL
0002 auto NPL = [](auto x) { return x ? x->npl : 0; }; //统一处置nullptr
0003 template <typename T> struct LeftHeap : public PQ<T>, public BinTree<T> { //左式堆
0004    LeftHeap(T* E, int n) //批量构造：可改进为Floyd算法
0005     { for (int i = 0; i < n; i++) insert(E[i]); }
0006    LeftHeap(LeftHeap& A, LeftHeap& B) { //通过融合的构造
0007       _root = meld(A._root, B._root);  _size = A._size + B._size;
0008       A._root = B._root = nullptr; A._size = B._size = 0;
0009    }
0010    void insert(T);  T delMax(); //插入与删除
0011    T& getMax() { return _root->data; } //堆顶即是最大元素
0012 }; //LeftHeap