#!/usr/bin/python

import numpy as np
import matplotlib.pyplot as plt

GRIDSIZE = 50      # grid size in x- and y-direction
INIT_CELLS = 1000  # number of cells initially set 'alive'


# query number of 'living' neighbours
def get_neighbours(grid, i, j):
    living  = 0
    """ Check all neighbours for status """
    """
    Insert your code here
    """
    living = grid[i-1,j] + grid[i-1,j+1] + grid[i,j+1] + grid[i+1,j+1] + grid[i+1,j] + grid[i+1,j-1] + grid[i,j-1] + grid[i-1,j-1]

    return living

# state transition t -> t + dt
def update(grid_old, grid_new):
    for i in range(1, GRIDSIZE+1):
        for j in range(1, GRIDSIZE+1):
            nln = get_neighbours(grid_old, i, j)
            
            """ Update cells according to rules using value 'nln' """
            """
            Insert your code here
            """
            if grid_old[i,j] == 0 and nln == 3:
                grid_new[i,j] = 1
            elif grid_old[i,j] == 1 and nln < 2:
                grid_new[i,j] = 0
            elif grid_old[i,j] == 1 and (nln == 2 or nln == 3):
                grid_new[i,j] = 1
            elif grid_old[i,j] == 1 and nln > 3:
                grid_new[i,j] == 0


# allocate memory and initialise grids
grid_old = np.zeros((GRIDSIZE+2, GRIDSIZE+2), dtype=np.int32)
grid_new = np.zeros((GRIDSIZE+2, GRIDSIZE+2), dtype=np.int32)

# set random starting points
no_repeat = []
for k in range(INIT_CELLS):
    i = int(float(GRIDSIZE)*np.random.random())+1
    j = int(float(GRIDSIZE)*np.random.random())+1

    grid_old[i,j] = 1

# run updates
plt.ion()
plt.imshow(grid_old)
plt.pause(0.1)
for t in range(50):
    plt.clf()
    update(grid_old, grid_new)
    for i in range(GRIDSIZE+2):
        for j in range(GRIDSIZE+2):
            grid_old[i,j] = grid_new[i,j]
            grid_new[i,j] = 0
    plt.imshow(grid_old)
    plt.pause(0.1)
plt.ioff()