75 lines
2.2 KiB
Python
75 lines
2.2 KiB
Python
#!/usr/bin/env python3
|
|
# coding: utf8
|
|
|
|
"""
|
|
Author: freezed <git@freezed.me> 2020-07-16
|
|
Licence: `GNU GPL v3` GNU GPL v3: http://www.gnu.org/licenses/
|
|
|
|
This file is part of [`free_zed/mypsb`](https://gitlab.com/free_zed/mypsb/)
|
|
"""
|
|
|
|
|
|
def main(pile, n):
|
|
"""
|
|
This function returns the situation of a sand `pile` after droping `n`
|
|
sand grain on top of it.
|
|
|
|
|
|
1. Sand pile is a square table of uneven size (viewed from up)
|
|
1. Sand grain is always dropped on center of pile.
|
|
1. When a cell had 4 grains inside, these grains moves on the near 4th cells
|
|
1. Grains going out the pile are losts
|
|
|
|
:Tests:
|
|
>>> main([[1,1,1],[1,1,1],[1,1,1]],1)
|
|
[[1, 1, 1], [1, 2, 1], [1, 1, 1]]
|
|
>>> main([[1,1,1],[1,1,1],[1,1,1]],2)
|
|
[[1, 1, 1], [1, 3, 1], [1, 1, 1]]
|
|
>>> main([[1,1,1],[1,1,1],[1,1,1]],3)
|
|
[[1, 2, 1], [2, 0, 2], [1, 2, 1]]
|
|
>>> main([[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1]],1)
|
|
[[1, 1, 1, 1, 1], [1, 1, 1, 1, 1], [1, 1, 2, 1, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1]]
|
|
>>> main([[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1]],3)
|
|
[[1, 1, 1, 1, 1], [1, 1, 2, 1, 1], [1, 2, 0, 2, 1], [1, 1, 2, 1, 1], [1, 1, 1, 1, 1]]
|
|
>>> main([[0,0,3,0,0],[0,0,3,0,0],[3,3,3,3,3],[0,0,3,0,0],[0,0,3,0,0]],1)
|
|
[[0, 1, 0, 1, 0], [1, 2, 2, 2, 1], [0, 2, 0, 2, 0], [1, 2, 2, 2, 1], [0, 1, 0, 1, 0]]
|
|
"""
|
|
|
|
size = len(pile)
|
|
x_max, y_max = size - 1, size - 1
|
|
center = int((size - 1) / 2)
|
|
|
|
while n != 0:
|
|
pile[center][center] += 1
|
|
|
|
# find cells > 3
|
|
for x in range(size):
|
|
|
|
for y in range(size):
|
|
|
|
if pile[x][y] > 3:
|
|
pile[x][y] -= 4
|
|
|
|
# update west neighbor
|
|
if x < x_max:
|
|
pile[x + 1][y] += 1
|
|
# update east neighbor
|
|
if x > 0:
|
|
pile[x - 1][y] += 1
|
|
# update north neighbor
|
|
if y < y_max:
|
|
pile[x][y + 1] += 1
|
|
# update south neighbor
|
|
if y > 0:
|
|
pile[x][y - 1] += 1
|
|
|
|
n -= 1
|
|
|
|
return pile
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|