堆排序伪代码

//建堆,运行时间的界T(n) =O(N)
BuildHeap(A)
        n = length(A)
        for  i = n/2 downto 1  do   //从非叶子节点开始，自底往上，使A变成最大堆
               Max_Heapify(A, i, n)
end
//调整为最大堆 ,T(n) = O(lgn)
Max_Heapify(A,idx,max) //idx：数组开始的下标，max：最大的数组下标
    left = 2*idx
    right = 2*idx
    if(leftA[idx]) then
        largest = left
    else
        largest = idx
    if(right < max and A[right]>A[largest]) then
        largest = ritht  
    if(largest != idx) then
        exchange A[largest] with A[idx]
        Max_Heapify(A,largest,max) //交换位置后，还需要调整它的子树
end
HeapSort(A)
      BuildHeap(A)
      for i = length(A) downto 2   do 
             exchange  A[1] with A[i] //把最大堆根节点与最后一个互换
             Max_Heapify(A,1, i-1) //把交互后的排除在堆之外，重新从1到i-1,调整堆
end