def heapSort(a):  
    def sift(start, count):  
        root = start  
  
        while root * 2 + 1 < count:  
            child = root * 2 + 1  
            if child < count - 1 and a[child] < a[child + 1]:  
                child += 1  
            if a[root] < a[child]:  
                a[root], a[child] = a[child], a[root]  
                root = child  
            else:  
                return  
  
    count = len(a)  
    start = count / 2 - 1  
    end = count - 1  
  
    while start >= 0:  
        sift(start, count)  
        start -= 1  
  
    while end > 0:  
        a[end], a[0] = a[0], a[end]  
        sift(0, end)  
        end -= 1  
  
a = [-8,0,1,3,11,35,68]  
heapSort(a)  
print a # [-8, 0, 1, 3, 11, 35, 68] 



#//python/4603