class BinaryHeap:

def __init__(self, n):

self.heap = [0] * n

self.size = 0

def remove_min(self):

removed = self.heap[0]

self.size -= 1

self.heap[0] = self.heap[self.size]

self._down(0)

return removed

def add(self, value):

self.heap[self.size] = value

self._up(self.size)

self.size += 1

def _up(self, pos):

while pos > 0:

parent = (pos - 1) // 2

if self.heap[pos] >= self.heap[parent]:

break

self.heap[pos], self.heap[parent] = self.heap[parent], self.heap[pos]

pos = parent

def _down(self, pos):

while True:

child = 2 * pos + 1

if child >= self.size:

break

if child + 1 < self.size and self.heap[child + 1] < self.heap[child]:

child += 1

if self.heap[pos] <= self.heap[child]:

break

self.heap[pos], self.heap[child] = self.heap[child], self.heap[pos]

pos = child

def test():

h = BinaryHeap(10)

h.add(3)

h.add(1)

h.add(2)

print(h.remove_min())

print(h.remove_min())

print(h.remove_min())

test()