Prokaryote Growths (2)

A petri dish is represented as a grid of size $N\times{M}$ , where:

B represents a bacterium
. represents an empty space

At each growth cycle, any bacteria spreads to its neighbouring positions in diagonal (up-left, up-right, down-left, down-right). Newborn bacteria are represented in lowercase (’b’)

Write a function growth_cycle(grid) that, given an $N\times{M}$ matrix representing the initial state of the colony, returns the state of the petri dish after one growth cycle.

EXAMPLES

	Example 1
Inital state		After 1 cycle (new cells in lowercase)
`. . . . . B .`		`. . b . b B .`
`. . . B . . .`		`. b . B b . b`
`B . . . . . .`		`B . b . b . b`
`. . . . . B .`		`. b . . . B .`
`. . . . . . .`		`. . . . b . b`

	Example 2
Inital state		After 1 cycle (new cells in lowercase)
`. . . . . . . .`		`. . b . b . . .`
`. . . B . . . .`		`. . . B . b . .`
`. . . . B . . .`		`. b b . B . . .`
`B . . . . . . .`		`B . . b . b . .`

	Example 3
Inital state		After 1 cycle (new cells in lowercase)
`. . . . . .`		`b . b . b .`
`. B . B . .`		`. B . B . .`
`B . . . . .`		`B . b . b .`
`. . . . . B`		`. b . . . B`
`. . . . . B`		`. . . . b B`
`. . . . . .`		`. . . . b .`

Observation

Process the dish positions from left to right and from top down. In case a cell is already occupied, it must not be overwritten with a newborn bacterium.
It may be useful to write a function inside(grid,p,q) that returns True if position (p,q) is inside the limits of grid, and False otherwise.

Important: Submit only the function. If you have a main program, comment it out or embed it inside a conditional clause if __name__ == "__main__":

Problem information

Author: Lluís Padró

Generation: 2026-07-03T11:14:46.720Z