def __init__(self, n):
self.n = n
self.union_alg = UnionQuickUnionWeighted((n * n) + 2)
self.top = (n * n)
self.bottom = (n * n) + 1
class Percolation(object):
def __init__(self, n):
self.n = n
self.union_alg = UnionQuickUnionWeighted((n * n) + 2)
self.top = (n * n)
self.bottom = (n * n) + 1
def _calculate_id(self, row, column):
"""
Calculates the id which is used in our QuickUnion class.
Take for example the following grid of n=5
0 1 2 3 4
5 6 7 8 9
10 11 12 13 14
15 16 17 18 19
20 21 22 23 24
To be able to do unions, we need to know the id
of any given x and y.
"""
return self.n * (row - 1) + column - 1
def open(self, row, column):
if row > self.n or column > self.n:
raise Exception("out of range")
id = self._calculate_id(row, column)
if row == 1:
self.union_alg.union(self.top, id)
if row == self.n:
self.union_alg.union(self.bottom, id)
# Union with its open neighbours
up = (row + 1, column)
down = (row - 1, column)
left = (row, column - 1)
right = (row, column + 1)
if up[0] <= self.n and self.is_open(*up):
up_id = self._calculate_id(*up)
self.union_alg.union(id, up_id)
if row > 1 and self.is_open(*down):
down_id = self._calculate_id(*down)
self.union_alg.union(id, down_id)
if right[1] <= self.n and self.is_open(*right):
right_id = self._calculate_id(*right)
self.union_alg.union(id, right_id)
if column > 1 and self.is_open(*left):
left_id = self._calculate_id(*left)
self.union_alg.union(id, left_id)
# In the union class set it as opened
self.union_alg.ids[id]['open'] = True
def percolates(self):
return self.union_alg.connected(self.top, self.bottom)
def is_open(self, x, y):
id_x_y = self._calculate_id(x, y)
return self.union_alg.ids[id_x_y].get('open', False)
def is_full(self, x, y):
id_x_y = self._calculate_id(x, y)
return self.union_alg.connected(id_x_y, self.top)
