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@The6P4C

The6P4C/sandpiles.py

Last active Jan 14, 2017
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class Sandpile:
def __init__(self, size, data=None):
self.size = size
if data:
assert(isinstance(data, list))
assert(len(data) == size)
for row in data:
assert(isinstance(row, list))
assert(len(row) == size)
for value in row:
assert(isinstance(value, int))
self.data = data
else:
self.data = [[0] * size for _ in range(0, size)]
def __add__(self, other):
def requires_toppling(data):
result = False
for row in data:
for value in row:
if value > 3:
result = True
return result
def get_neighbours(row_index, column_index, size):
results = []
for row_offset, column_offset in [(0, -1), (1, 0), (0, 1), (-1, 0)]:
new_row_index = row_index + row_offset
new_column_index = column_index + column_offset
is_row_valid = new_row_index >= 0 and new_row_index < size
is_column_valid = new_column_index >= 0 and new_column_index < size
if is_row_valid and is_column_valid:
results.append((new_row_index, new_column_index))
return results
assert(self.size == other.size)
size = self.size
# clone data
new_data = [row[:] for row in self.data]
for row_index, row in enumerate(other.data):
for column_index, value in enumerate(row):
new_data[row_index][column_index] += value
while requires_toppling(new_data):
toppled_data = [row[:] for row in new_data]
for row_index, row in enumerate(toppled_data):
for column_index, value in enumerate(row):
if value > 3:
toppled_data[row_index][column_index] = value % 4
amount_to_topple = value // 4
neighbours = get_neighbours(row_index, column_index, size)
for neighbour_row_index, neighbour_column_index in neighbours:
toppled_data[neighbour_row_index][neighbour_column_index] += amount_to_topple
new_data = toppled_data
return Sandpile(size, data=new_data)
def _data_to_string(self, data):
maximum_value_length = 0
for row in data:
for value in row:
maximum_value_length = max(maximum_value_length, len(str(value)))
row_strs = []
for row in data:
value_strs = []
for value in row:
# pad the value out to the required length
value_str = '{0: >{1}}'.format(value, maximum_value_length)
value_strs.append(value_str)
row_strs.append(' '.join(value_strs))
return '\n'.join(row_strs)
def __str__(self):
return self._data_to_string(self.data)
a_data = [
[2, 1, 2],
[1, 0, 1],
[2, 1, 2]
]
a = Sandpile(3, data=a_data)
b_data = [
[2, 2, 2],
[2, 2, 2],
[2, 2, 2]
]
b = Sandpile(3, data=b_data)
print(a + b)
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