Love to Code?

Just saw a facebook advertisemet with the title "Love to Code?" and couldn't resist the temptation to click on it.   It ended up being a door to facebook recruitement process and I decided to spend some minutes to try to get more information on how their process is.

After clicking the ad you are redirected to a very interesting tool from an external company called InterviewStreet who asked me to solve a simple programming problem in less than an hour in any programming language.

The problem was a slightly modified version of the game of life problem where the pieces at the boundaries never change and I decided to solve it in python. I was slightly disappointed because I was really expecting something more difficult (Tuenti contest problems are more difficult for example).

I was able to finish it in the 1h timeframe but didn't pay too much attention to write a great code so they won't probably call me :-)    Find my code below in case somebody wants to improve it.

#Enter your code here. Read input from STDIN. Print output to STDOUT

#For more details, please check http://www.interviewstreet.com/recruit/challenges/faq/view#stdio

def solve(board, size):

  result = [list(row) for row in board]

  pos = [(-1, -1),(-1, 0),(-1, 1),(0, -1),(0, 0),(0, 1),(1, -1),(1, 0),(1, 1)]

  for y in range(1, size-1):

    for x in range(1, size-1):

      blacks = whites = 0

      for dx,dy in pos:

        if 0 <= y+dy < size and 0 <= x+dx < size:

          if board[y+dy][x+dx] == 'b':

            blacks += 1

          else:

            whites += 1

      result[y][x] = ('b' if blacks > whites else 'w')

  return [''.join(row) for row in result]

tests = raw_input()

for test in range(int(tests)):

  #read input

  size, iters = raw_input().split(' ')

  board = [''] * int(size)

  for i in range(int(size)):

    board[i] = raw_input()

  #calculate

  for i in range(int(iters)):

    board = solve(board, int(size))

  #write result

  print "Board %d" % (test+1)

  for row in board:

    print row