Day 12: Christmas Tree Farm

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FAQ

  • CameronDevOPM
    2·
    3 days ago

    Rust

    Its not Christmas, but this one was a gift :D. Merry Christmas all, thanks for everyone who has contributed solutions!

    Rest easy little advent bot, your work is done now.

    spoiler 
        struct Tree {
        w: u32,
        h: u32,
        presents: Vec<u32>,
    }

    fn is_solveable(tree: &Tree) -> bool {
        if tree.h * tree.w < tree.presents.iter().sum::<u32>() * 9 {
            return false;
        }
        true
    }

    #[test]
    fn test_y2025_day12_part1() {
        let input = include_str!("../../input/2025/day_12.txt");
        let parts = input.split("\n\n").collect::<Vec<_>>();

        let trees: Vec<Tree> = parts
            .last()
            .unwrap()
            .lines()
            .map(|line| {
                let parts: (&str, &str) = line.split_once(": ").unwrap();
                let [w, h] = parts
                    .0
                    .split("x")
                    .map(u32::from_str)
                    .map(Result::unwrap)
                    .collect::<Vec<_>>()[..]
                else {
                    unreachable!()
                };
                let num_presents = parts
                    .1
                    .split(" ")
                    .map(u32::from_str)
                    .map(Result::unwrap)
                    .collect::<Vec<_>>();
                Tree {
                    w,
                    h,
                    presents: num_presents,
                }
            })
            .collect();

        let mut solvable = 0;
        for tree in trees {
            if is_solveable(&tree) {
                solvable += 1;
            }
        }
        println!("solvable: {}", solvable);
    }