Prokaryote Growths (1)

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, each bacterium spreads to its neighboring cells in horitzontal and vertical directions (i.e., up, down, left, right).

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 boldface)
`. . . . . B .`		`. . .``B``B``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 boldface)
`. . . . . . . .`		`. . .``B``. . . .`
`. . . B . . . .`		`. .``B``B``B``. . .`
`. . . B . . . .`		`B``.``B``B``B``. . .`
`B . . . . . . .`		`B``B``.``B``. . . .`

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

Observation

In order to avoid spreading newly born cells, use a new matrix to store the new status of the dish.
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: 2026-05-08T13:46:45.020Z