Straightforward clear solution for Moore Neighbourhood by nickie - python coding challenges

Enable Javascript in your browser and then refresh this page, for a much enhanced experience.

Straightforward solution in Clear category for Moore Neighbourhood by nickie

def count_neighbours(grid, row, col):
    N, M = len(grid), len(grid[0])
    NEIGHBOURS = [(-1,-1),(-1,0),(-1,1),(0,-1),(0,1),(1,-1),(1,0),(1,1)]
    return sum(0 <= row+i < N and 0 <= col+j < M and grid[row+i][col+j]
               for i, j in NEIGHBOURS)

Oct. 6, 2014

Comments:

mlb00 on March 24, 2015, 1:28 a.m.
pretty short!

Jemmity on April 26, 2015, 9:12 a.m.
Great - clear and concise.

jgo3000 on April 28, 2015, 5 p.m.
Well done. I am still trying to understand how it works. So you iterate through the tuple pairs in your NEIGHBOURS list checking first to see if the row is within the boundaries of the grid, then the same for the columns and then to see which "neighbours" of the actual target cell contains a 1 (and then sum them). Please let me know if I missed something or that is inaccurate. Thanks.

nickie on April 28, 2015, 8:19 p.m.
That's right.

jgo3000 on May 1, 2015, 9:21 p.m.
Thanks!

Cybernick on June 1, 2015, 10:19 p.m.
Nice.

aimar on June 13, 2015, 4:57 a.m.
<blockquote> NEIGHBOURS = [(-1,-1),(-1,0),(-1,1),(0,-1),(0,1),(1,-1),(1,0),(1,1)] </blockquote> looks like indian code

nickie on June 13, 2015, 1:14 p.m.
Sorry, I don't understand what you mean... I'm no indian, but should I take it as a compliment? :-)

dhs789520 on Nov. 29, 2015, 4:30 p.m.
you're a real hack

a354913 on Dec. 2, 2015, 3:57 p.m.
I like "explicit cells" solutions for this task. Your code seems the best of them (and best of all solutions), although I haven't check a lot of solutions so far. It took me a half of the second to understand that the code does some neighbor checking in multi-dimensional array. In case of some good-written library, there also will be a nice doc-string explaining what exactly the last line does, so, I don't need to sit with piece of paper and pencil figuring out what the clever one-liners does. However, most of the time I don't need an exact technique explanation, but just "fix" where the neighbor checking is performed in the lib and continue to read sources.

serg3y1999 on Aug. 26, 2018, 11:27 a.m.
so understandable,well !

GitHub

0 %

PyCharm The Python IDE for Professional Developers. Enjoy productive Python, web and scientific development with PyCharm. Download it now!