0001 template <typename T> void siftUp(T* A, Rank i) { //0 <= i < _size
0002    T e = A[i]; //上滤者先备份，然后让小的祖先顺次下移
0003    for (Rank j;  (0 < i) && (A[j = PARENT(i)] < e);  A[i] = A[j], i = j);
0004    A[i] = e; //上滤者最终就位
0005 } //siftUp