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//! # Day 20: Donut Maze
//!
//! You notice a strange pattern on the surface of Pluto and land nearby to get a closer look. Upon
//! closer inspection, you realize you've come across one of the famous space-warping mazes of the
//! long-lost Pluto civilization!
//!
//! Because there isn't much space on Pluto, the civilization that used to live here thrived by
//! inventing a method for folding spacetime. Although the technology is no longer understood, mazes
//! like this one provide a small glimpse into the daily life of an ancient Pluto citizen.
//!
//! This maze is shaped like a [donut]. Portals along the inner and outer edge of the donut can
//! instantly teleport you from one side to the other. For example:
//!
//! ```txt
//!          A
//!          A
//!   #######.#########
//!   #######.........#
//!   #######.#######.#
//!   #######.#######.#
//!   #######.#######.#
//!   #####  B    ###.#
//! BC...##  C    ###.#
//!   ##.##       ###.#
//!   ##...DE  F  ###.#
//!   #####    G  ###.#
//!   #########.#####.#
//! DE..#######...###.#
//!   #.#########.###.#
//! FG..#########.....#
//!   ###########.#####
//!              Z
//!              Z
//! ```
//!
//! This map of the maze shows solid walls (`#`) and open passages (`.`). Every maze on Pluto has a
//! start (the open tile next to `AA`) and an end (the open tile next to `ZZ`). Mazes on Pluto also
//! have portals; this maze has three pairs of portals: `BC`, `DE`, and `FG`. When on an open tile
//! next to one of these labels, a single step can take you to the other tile with the same label.
//! (You can only walk on `.` tiles; labels and empty space are not traversable.)
//!
//! One path through the maze doesn't require any portals. Starting at `AA`, you could go down 1,
//! right 8, down 12, left 4, and down 1 to reach `ZZ`, a total of 26 steps.
//!
//! However, there is a shorter path: You could walk from `AA` to the inner `BC` portal (4 steps),
//! warp to the outer `BC` portal (1 step), walk to the inner `DE` (6 steps), warp to the outer `DE`
//! (1 step), walk to the outer `FG` (4 steps), warp to the inner `FG` (1 step), and finally walk to
//! `ZZ` (6 steps). In total, this is only **23** steps.
//!
//! Here is a larger example:
//!
//! ```txt
//!                    A
//!                    A
//!   #################.#############
//!   #.#...#...................#.#.#
//!   #.#.#.###.###.###.#########.#.#
//!   #.#.#.......#...#.....#.#.#...#
//!   #.#########.###.#####.#.#.###.#
//!   #.............#.#.....#.......#
//!   ###.###########.###.#####.#.#.#
//!   #.....#        A   C    #.#.#.#
//!   #######        S   P    #####.#
//!   #.#...#                 #......VT
//!   #.#.#.#                 #.#####
//!   #...#.#               YN....#.#
//!   #.###.#                 #####.#
//! DI....#.#                 #.....#
//!   #####.#                 #.###.#
//! ZZ......#               QG....#..AS
//!   ###.###                 #######
//! JO..#.#.#                 #.....#
//!   #.#.#.#                 ###.#.#
//!   #...#..DI             BU....#..LF
//!   #####.#                 #.#####
//! YN......#               VT..#....QG
//!   #.###.#                 #.###.#
//!   #.#...#                 #.....#
//!   ###.###    J L     J    #.#.###
//!   #.....#    O F     P    #.#...#
//!   #.###.#####.#.#####.#####.###.#
//!   #...#.#.#...#.....#.....#.#...#
//!   #.#####.###.###.#.#.#########.#
//!   #...#.#.....#...#.#.#.#.....#.#
//!   #.###.#####.###.###.#.#.#######
//!   #.#.........#...#.............#
//!   #########.###.###.#############
//!            B   J   C
//!            U   P   P
//! ```
//!
//! Here, `AA` has no direct path to `ZZ`, but it does connect to `AS` and `CP`. By passing through
//! `AS`, `QG`, `BU`, and `JO`, you can reach `ZZ` in **58** steps.
//!
//! In your maze, **how many steps does it take to get from the open tile marked AA to the open tile
//! marked `ZZ`?**
//!
//! [donut]: https://en.wikipedia.org/wiki/Torus

use anyhow::Result;

pub const INPUT: &str = include_str!("d20.txt");

pub fn solve_part_one(input: &str) -> Result<i64> {
    Ok(0)
}

pub fn solve_part_two(input: &str) -> Result<i64> {
    Ok(0)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn part_one() {}

    #[test]
    fn part_two() {}
}