Question

1) Rewrite this heapify method RECURSIVELY in Python.
def heapify(self):   # assumes left subtree and right subtree are valid heaps
        current=0
        done=False
        while not done:
            left=Heap._left(current)  
            right=Heap._right(current)
            # if left exists, compare to current
            if leftself.data[current]:
                bigger=left
            else:
                bigger=current
            if rightself.data[bigger]:
                bigger=right
            if bigger==current:
                done=True
            else:
                self.data[current],self.data[bigger]=self.data[bigger],self.data[current]
                current=bigger

Answer 1

# the entire logic is same as your method , just remove the while loop
# and execute the task inside while loop recursively by calling the heapify method again
# at the end of swapping logic for getting biggest for each root.

def heapify(data, size, index):
    bigger = index
    left = 2 * index + 1
    right = 2 * index + 2

    if left < size and data[index] < data[left]:
        bigger = left

    if right < size and data[bigger] < data[right]:
        bigger = right

    if bigger != index:
        data[index], data[bigger] = data[bigger], data[index]
        # recursive call to heapify method
        heapify(data, size, bigger)