算法：堆排序

MAX-HEAPIFY(A, i)
    left  =left(i)
    right=right(i)
    if(left<=heap-size[A] and A[left]>A[i])
        then largest=left
        else   largest=i
    if(right<=heap-size[A] and A[right]>A[largest])
        then largest=right
    if(largest!=i)
        then exchange(A[i], A[largest])
                MAX-HEAPIFY(A, largest)

BULD-MAX-HEAP(A)
    heap-size[A]=legnth(A)
    for i=floor(length(A)/2) downto 1
        do MAX_HEAPIFY(A, i)

HEAP-SORT(A)
    BUILD-MAX-HEAP(A)
    for i=length(A) downto 2
        do exchange(A[1], A[i])
           heap-size(A)=heap-size[A]-1
           MAX-HEAPIFY(A, 1)