Geometry problems are quite niche and I have really only ever encountered a small handful of them myself. Advent of Code 2023 was where I developed these pointers


Check if point is inside polygon

Otherwise known to be raycasting, crossing number algorithm, or the even-odd rule algorithm

  • From point (x,y)(x, y), draw a line infinitely long in 1 direction and check how many sides of the polygon it intersects

    • If intersect odd number of points, inside polygon

    • Otherwise, outside of polygon

  • Ensure to check for corner pieces such as L and 7 pieces and do not count those

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