day 01

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.lock

@@ -0,0 +1,32 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day-01"
+version = "0.1.0"
+dependencies = [
+ "nom",
+]
+
+[[package]]
+name = "memchr"
+version = "2.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f665ee40bc4a3c5590afb1e9677db74a508659dfd71e126420da8274909a0167"
+
+[[package]]
+name = "minimal-lexical"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
+[[package]]
+name = "nom"
+version = "7.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d273983c5a657a70a3e8f2a01329822f3b8c8172b73826411a55751e404a0a4a"
+dependencies = [
+ "memchr",
+ "minimal-lexical",
+]

Cargo.toml

@@ -0,0 +1,8 @@
+[workspace]
+resolver = "2"
+members = [
+    "day-01",
+]
+
+[workspace.dependencies]
+nom = "7.1.3"

day-01/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day-01"
+version = "0.1.0"

day-01/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day-01"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nom = "7.1.3"

day-01/src/bin/part1.rs

@@ -0,0 +1,33 @@
+fn main() {
+    let input = include_str!("./input1.txt");
+    println!("{}", part1(input));
+}
+
+fn part1(input: &str) -> u32 {
+    input.lines().map(line).sum()
+}
+
+fn line(input: &str) -> u32 {
+    let mut numbers = input.chars().filter_map(|c| c.to_digit(10)).peekable();
+    let first = numbers.peek().unwrap().to_owned();
+    let last = numbers.last().unwrap();
+    (first * 10) + last
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() {
+        assert_eq!(part1("1abc2\npqr3stu8vwx\na1b2c3d4e5f\ntreb7uchet"), 142);
+    }
+
+    #[test]
+    fn test_line1() {
+        assert_eq!(line("1abc2"), 12);
+        assert_eq!(line("pqr3stu8vwx"), 38);
+        assert_eq!(line("a1b2c3d4e5f"), 15);
+        assert_eq!(line("treb7uchet"), 77);
+    }
+}

day-01/src/bin/part2.rs

@@ -0,0 +1,64 @@
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::anychar,
+    combinator::{map, map_opt, value},
+    multi::many1,
+    IResult,
+};
+
+fn main() {
+    let input = include_str!("./input2.txt");
+    println!("{}", part2(input));
+}
+
+fn part2(input: &str) -> u32 {
+    input.lines().map(line).sum()
+}
+
+fn line(input: &str) -> u32 {
+    let digits = many1(alt((map(digit, Some), value(None, anychar))))(input)
+        .unwrap()
+        .1;
+    let mut digits = digits.iter().filter_map(|d| d.to_owned()).peekable();
+    let first = digits.peek().unwrap().to_owned();
+    let last = digits.last().unwrap();
+
+    (first * 10) + last
+}
+
+fn digit(i: &str) -> IResult<&str, u32> {
+    alt((
+        map_opt(anychar, |c| c.to_digit(10)),
+        value(1, tag("one")),
+        value(2, tag("two")),
+        value(3, tag("three")),
+        value(4, tag("four")),
+        value(5, tag("five")),
+        value(6, tag("six")),
+        value(7, tag("seven")),
+        value(8, tag("eight")),
+        value(9, tag("nine")),
+    ))(i)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part2() {
+        assert_eq!(part2("two1nine\neightwothree\nabcone2threexyz\nxtwone3four\n4nineeightseven2\nzoneight234\n7pqrstsixteen"), 281);
+    }
+
+    #[test]
+    fn test_line2() {
+        assert_eq!(line("two1nine"), 29);
+        assert_eq!(line("eightwothree"), 83);
+        assert_eq!(line("abcone2threexyz"), 13);
+        assert_eq!(line("xtwone3four"), 24);
+        assert_eq!(line("4nineeightseven2"), 42);
+        assert_eq!(line("zoneight234"), 14);
+        assert_eq!(line("7pqrstsixteen"), 76);
+    }
+}