Advent of Code 2023 - Day 18

[Allianzcortex]

create a 1000 × 1000 grid and use (200,200) as the start point to draw the grid(an arbitrary number). After deciding the trench location, then using BFS to keep iterating the whole grid.

traverse func will return a bool to indicate whether it's inside the trench or or outside of trench(ie its out of boundary of grid), then keep filling grid with different indexes and recalculate it finally.