solution: day6

Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc936419f96fa211c1b9166887b38e5e40b19958e5b895be7c1f93adec7071ac"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "aoc"
 version = "0.1.0"
@@ -11,6 +20,7 @@ dependencies = [
  "itertools",
  "lazy_static",
  "pico-args",
+ "regex",
  "reqwest",
  "rust-crypto",
 ]
@@ -591,6 +601,23 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "regex"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e076559ef8e241f2ae3479e36f97bd5741c0330689e217ad51ce2c76808b868a"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"

Cargo.toml

@@ -13,5 +13,6 @@ hex-literal = "0.3.4"
 itertools = "0.10.5"
 lazy_static = "1.4.0"
 pico-args = "0.5.0"
+regex = "1.7.0"
 reqwest = { version = "0.11.13", features = ["blocking"] }
 rust-crypto = "0.2.36"

src/bin/06.rs

@@ -0,0 +1,139 @@
+use std::collections::HashMap;
+
+use lazy_static::lazy_static;
+use regex::Regex;
+use Instruction::*;
+
+#[derive(Debug)]
+struct Point {
+    x: u32,
+    y: u32,
+}
+
+impl FromIterator<u32> for Point {
+    fn from_iter<T: IntoIterator<Item = u32>>(iter: T) -> Self {
+        let mut it = iter.into_iter();
+        Point {
+            x: it.next().unwrap(),
+            y: it.next().unwrap(),
+        }
+    }
+}
+
+#[derive(Debug)]
+enum Instruction {
+    On,
+    Off,
+    Toggle,
+}
+
+#[derive(Debug)]
+struct Command {
+    instruction: Instruction,
+    from: Point,
+    to: Point,
+}
+
+impl From<&str> for Command {
+    fn from(value: &str) -> Self {
+        lazy_static! {
+            static ref RE: Regex = Regex::new(
+                r"(turn on|turn off|toggle) (\d{1,3},\d{1,3}) through (\d{1,3},\d{1, 3})"
+            )
+            .unwrap();
+        }
+
+        let capture = RE.captures(value).unwrap();
+
+        let instruction = match capture[1].as_ref() {
+            "turn on" => On,
+            "turn off" => Off,
+            "toggle" => Toggle,
+            _ => unreachable!(),
+        };
+
+        let from: Point = capture[2]
+            .split(',')
+            .map(|x| x.parse::<u32>().unwrap())
+            .collect();
+
+        let to: Point = capture[3]
+            .split(',')
+            .map(|x| x.parse::<u32>().unwrap())
+            .collect();
+
+        Command {
+            instruction,
+            from,
+            to,
+        }
+    }
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let mut map = HashMap::<(u32, u32), bool>::new();
+    for line in input.trim().split('\n') {
+        let Command {
+            instruction,
+            from,
+            to,
+        } = Command::from(line);
+        for x in from.x..=to.x {
+            for y in from.y..=to.y {
+                match instruction {
+                    On => *map.entry((x, y)).or_default() = true,
+                    Off => *map.entry((x, y)).or_default() = false,
+                    Toggle => {
+                        map.entry((x, y)).or_default();
+                        map.insert((x, y), !map[&(x, y)]);
+                    }
+                }
+            }
+        }
+    }
+    Some(map.values().filter(|&x| *x).count() as u32)
+}
+pub fn part_two(input: &str) -> Option<u32> {
+    let mut map = HashMap::<(u32, u32), u32>::new();
+    for line in input.trim().split('\n') {
+        let Command {
+            instruction,
+            from,
+            to,
+        } = Command::from(line);
+        for x in from.x..=to.x {
+            for y in from.y..=to.y {
+                match instruction {
+                    On => *map.entry((x, y)).or_default() += 1,
+                    Toggle => *map.entry((x, y)).or_default() += 2,
+                    Off => {
+                        map.entry((x, y)).or_default();
+                        if map[&(x, y)] > 0 {
+                            *map.entry((x, y)).or_default() -= 1;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    Some(map.values().into_iter().sum())
+}
+fn main() {
+    let input = &aoc::read_file("inputs", 6);
+    aoc::solve!(1, part_one, input);
+    aoc::solve!(2, part_two, input);
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_part_one() {
+        let input = aoc::read_file("test_inputs", 6);
+        assert_eq!(part_one(&input), Some(998996));
+    }
+    #[test]
+    fn test_part_two() {
+        let input = aoc::read_file("test_inputs", 6);
+        assert_eq!(part_two(&input), Some(1001996));
+    }
+}

src/test_inputs/06.txt

@@ -0,0 +1,3 @@
+turn on 0,0 through 999,999
+toggle 0,0 through 999,0
+turn off 499,499 through 500,500