Day 18 aoc in progress, not liking rust today

advent_of_code/2022/18/src/main.rs

@@ -0,0 +1,124 @@
+use std::cmp::max;
+use std::fmt::{Display, Formatter, Result};
+use std::vec;
+
+use nom::{
+    bytes::streaming::tag,
+    character::complete::{self, multispace1},
+    multi::separated_list1,
+    sequence::{terminated, tuple},
+    IResult, Parser,
+};
+
+#[derive(Debug, Clone, Copy)]
+struct Coord {
+    x: u32,
+    y: u32,
+    z: u32,
+}
+
+impl Display for Coord {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{},{},{}", self.x, self.y, self.z)
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+struct LavaBlob {
+    coord: Coord,
+    number_of_neighbours: u32,
+}
+
+type LavaGrid = Vec<Vec<Vec<Option<LavaBlob>>>>;
+
+fn parse_input(input: &str) -> IResult<&str, Vec<Coord>> {
+    let (input, coords) = separated_list1(
+        multispace1,
+        tuple((
+            terminated(complete::u32, tag(",")),
+            terminated(complete::u32, tag(",")),
+            complete::u32,
+        ))
+        .map(|(x, y, z)| Coord { x, y, z }),
+    )(input)?;
+
+    Ok((input, coords))
+}
+
+fn main() {
+    let input_text = include_str!("../test.txt");
+    let (_rest, coordinates) = parse_input(input_text).unwrap();
+
+    // Test the parsing
+    println!("Testing the parsing");
+    for coord in &coordinates {
+        println!("{}", coord);
+    }
+    println!();
+
+    let max_grid_value = coordinates
+        .iter()
+        .map(|&coord| max(max(coord.x, coord.y), coord.z))
+        .max()
+        .unwrap() as usize;
+    let mut lava_grid: LavaGrid =
+        vec![vec![vec![None; max_grid_value + 1]; max_grid_value + 1]; max_grid_value + 1];
+
+    for coord in &coordinates {
+        let mut number_of_neighbours = 6;
+        let x = coord.x;
+        let y = coord.y;
+        let z = coord.z;
+
+        let mut coords_to_check = vec![];
+        if x > 0 {
+            coords_to_check.push(Coord { x: x - 1, y, z });
+        }
+        if x < max_grid_value as u32 {
+            coords_to_check.push(Coord { x: x + 1, y, z });
+        }
+        if y > 0 {
+            coords_to_check.push(Coord { x, y: y - 1, z });
+        }
+        if y < max_grid_value as u32 {
+            coords_to_check.push(Coord { x, y: y + 1, z });
+        }
+        if z > 0 {
+            coords_to_check.push(Coord { x, y, z: z - 1 })
+        }
+        if z < max_grid_value as u32 {
+            coords_to_check.push(Coord { x, y, z: z + 1 });
+        }
+
+        for coord_to_check in &coords_to_check {
+            match lava_grid[coord_to_check.x as usize][coord_to_check.y as usize]
+                [coord_to_check.z as usize]
+            {
+                None => continue,
+                Some(mut blob) => {
+                    number_of_neighbours -= 1;
+                    blob.number_of_neighbours -= 1;
+                }
+            }
+        }
+
+        lava_grid[x as usize][y as usize][z as usize] = Some(LavaBlob {
+            coord: coord.clone(),
+            number_of_neighbours,
+        })
+    }
+
+    let mut surface_area = 0;
+    for layer in &lava_grid {
+        for row in layer {
+            for optional_blob in row {
+                match optional_blob {
+                    None => continue,
+                    Some(blob) => surface_area += blob.number_of_neighbours,
+                }
+            }
+        }
+    }
+
+    println!("Surface area: {}", surface_area);
+}