Add leading 0s to the single digit day crates

2022/day09/Cargo.lock

@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day9"
+version = "0.1.0"
+dependencies = [
+ "geometry",
+]
+
+[[package]]
+name = "geometry"
+version = "0.1.0"

2022/day09/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day9"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+geometry = { path = "../geometry" }

2022/day09/src/main.rs

@@ -0,0 +1,100 @@
+use geometry::{Direction, Point};
+use std::collections::HashSet;
+use std::{env, fs};
+
+type SignedPoint = Point;
+
+struct Rope {
+    nodes: Vec<SignedPoint>,
+}
+
+impl Rope {
+    fn with_length(length: usize) -> Rope {
+        Rope {
+            nodes: vec![SignedPoint::zero(); length],
+        }
+    }
+
+    fn move_head(&mut self, direction: Direction) {
+        if let Some(head) = self.nodes.first_mut() {
+            head.move_by_one_in(direction);
+            for i in 1..self.nodes.len() {
+                let first = self.nodes[i - 1].clone();
+                let mut second = self.nodes.get_mut(i).unwrap();
+
+                let distance = second.distance_to(&first);
+                if distance.0 == 2 {
+                    second.x += 1;
+                    if distance.1 < 0 {
+                        second.y -= 1;
+                    } else if distance.1 > 0 {
+                        second.y += 1;
+                    }
+                } else if distance.0 == -2 {
+                    second.x -= 1;
+                    if distance.1 < 0 {
+                        second.y -= 1;
+                    } else if distance.1 > 0 {
+                        second.y += 1;
+                    }
+                } else if distance.1 == 2 {
+                    second.y += 1;
+                    if distance.0 < 0 {
+                        second.x -= 1;
+                    } else if distance.0 > 0 {
+                        second.x += 1;
+                    }
+                } else if distance.1 == -2 {
+                    second.y -= 1;
+                    if distance.0 < 0 {
+                        second.x -= 1;
+                    } else if distance.0 > 0 {
+                        second.x += 1;
+                    }
+                }
+            }
+        }
+    }
+}
+
+pub fn main() {
+    let args: Vec<String> = env::args().collect();
+
+    let filename = args.get(1).expect("Missing filename argument");
+
+    let file_contents = fs::read_to_string(&filename).expect("Unable to read file");
+
+    let mut visited_points: HashSet<SignedPoint> = HashSet::new();
+    let mut long_rope_visited_points: HashSet<SignedPoint> = HashSet::new();
+
+    let mut rope = Rope::with_length(2);
+    let mut long_rope = Rope::with_length(10);
+
+    for line in file_contents.lines() {
+        let mut split_line = line.split(" ");
+
+        let direction = Direction::from_relative_direction(split_line.next().unwrap()).unwrap();
+        let count = u8::from_str_radix(split_line.next().unwrap(), 10).unwrap();
+
+        for _ in 0..count {
+            rope.move_head(direction);
+            if let Some(last_node) = rope.nodes.last() {
+                visited_points.insert(last_node.clone());
+            }
+
+            long_rope.move_head(direction);
+            if let Some(last_node) = long_rope.nodes.last() {
+                long_rope_visited_points.insert(last_node.clone());
+            }
+        }
+    }
+
+    println!(
+        "Part 1: number of points tail node visited: {}",
+        &visited_points.len()
+    );
+    println!(
+        "Part 2: number of points tail node of long rope visited: {}",
+        &long_rope_visited_points.len()
+    );
+}