}
  //构造一个二叉堆；小顶堆
  void BuildHeap(HuffmanTree t, int len)
  {
  for (int i=len/2+len%2; i>0; i--)
  {
  PercDown(t, i, len);
  }
  }
  //构造二叉堆的功能子函数
  void PercDown(HuffmanTree t, int pos, int len)
  {
  int child;
  struct hNode min = t[pos];
  while (pos * 2 <= len)
  {
  child = pos * 2;
  if (child != len && t[child+1].weight < t[child].weight)
  child++;
  if (min.weight > t[child].weight)
  t[pos] = t[child];
  else
  break;
  pos = child;
  }
  t[pos] = min;
  }
  //删除二叉堆的根，并通过上移使得新得到的序列仍为二叉堆
  void DeleteMin(HuffmanTree t, int len)
  {
  struct hNode last = t[len--];//二叉堆的最后一个元素
  int child, pos = 1;
  while (pos * 2 <= len) //把二叉堆的某些元素往前移，使得新得到的序列仍为二叉堆
  {
  child = pos * 2;

[1]  [2]  [3]  [4]  [5]  [6]  [7]  [8]  [9]  [10]