Navigation · Maps and Costmaps · M2-L3 · Intermediate
Find the Ghost Obstacles
14:05. A cart was parked in the east hallway at noon and taken away at one. Scout still drives around it, and the nurses have started calling the empty spot "the ghost". Later the open doorway at the end of the hall gets a wall that nobody built.
Both problems are in how the obstacle layer handles what the laser says. You will trace a beam through the grid, clear what it passes through, mark only what it hits, and handle a beam that returns nothing.
Your task
Lab complete: post-mortem
You have passed every stage. Now connect it back to the theory and move on:
Output
What Python can I use?
Plain Python with math and heapq. Your code runs in a background worker: an endless loop is stopped after a few seconds and the page stays usable. It runs in your browser and is never sent anywhere.