2015: day01: finish

Cargo.lock

@@ -1,5 +1,9 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aoc2015"
+version = "0.1.0"
+
 [[package]]
 name = "aoc2018"
 version = "0.1.0"

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+    "aoc2015",
     "aoc2018",
     "aoc2019",
 ]

aoc2015/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "aoc2015"
+version = "0.1.0"
+authors = ["Antoine Martin <antoine97.martin@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

aoc2015/src/day01.rs

@@ -0,0 +1,81 @@
+use std::error::Error;
+
+use super::err;
+use super::Result;
+
+const INPUT: &str = include_str!("../input/day01.txt");
+
+pub fn run() -> Result<()> {
+    println!("part 1: {}", part1(INPUT)?);
+    println!("part 2: {}", part2(INPUT)?);
+
+    Ok(())
+}
+
+fn part1(input: &str) -> Result<i64> {
+    Ok(input
+        .chars()
+        .filter_map(|c| match c {
+            '(' => Some(1),
+            ')' => Some(-1),
+            _ => None,
+        })
+        .sum())
+}
+
+fn part2(input: &str) -> Result<usize> {
+    let mut sum = 0;
+    let mut res = 0;
+
+    for (i, c) in input.chars().enumerate() {
+        match c {
+            '(' => sum += 1,
+            ')' => sum -= 1,
+            _ => return Err(err!("unidentified character in input: {}", c)),
+        };
+
+        if sum < 0 {
+            res = i + 1;
+            break;
+        }
+    }
+
+    match res {
+        0 => Err(err!("never reached the basement...")),
+        _ => Ok(res),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn part1_provided() {
+        assert_eq!(part1("(())").unwrap(), 0);
+        assert_eq!(part1("()()").unwrap(), 0);
+        assert_eq!(part1("(((").unwrap(), 3);
+        assert_eq!(part1("(()(()(").unwrap(), 3);
+        assert_eq!(part1("))(((((").unwrap(), 3);
+        assert_eq!(part1("())").unwrap(), -1);
+        assert_eq!(part1("))(").unwrap(), -1);
+        assert_eq!(part1(")))").unwrap(), -3);
+        assert_eq!(part1(")())())").unwrap(), -3);
+    }
+
+    #[test]
+    fn part1_real() {
+        assert_eq!(part1(INPUT).unwrap(), 74);
+    }
+
+    #[test]
+    fn part2_provided() {
+        assert_eq!(part2(")").unwrap(), 1);
+        assert_eq!(part2("()())").unwrap(), 5);
+    }
+
+    #[test]
+    fn part2_real() {
+        assert_eq!(part2(INPUT).unwrap(), 1795);
+    }
+}

aoc2015/src/lib.rs

@@ -0,0 +1,8 @@
+pub mod day01;
+
+pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
+
+#[macro_export]
+macro_rules! err {
+    ($($string:expr),+) => (Box::<dyn Error>::from(format!($($string),+)))
+}

aoc2015/src/main.rs

@@ -0,0 +1,29 @@
+use std::env;
+
+use aoc2015::day01;
+
+use aoc2015::Result;
+
+fn main() -> Result<()> {
+    let days: &[fn() -> Result<()>] = &[day01::run];
+
+    let mut args = env::args();
+    args.next();
+
+    match args.next() {
+        Some(arg) => {
+            let day: usize = arg.parse().expect("Please provide a day number");
+            days[day - 1]().expect("error running day specified");
+        }
+        None => {
+            for (i, day) in days.iter().enumerate() {
+                let i = i + 1;
+                println!("day{}: ", i);
+                day().unwrap_or_else(|e| panic!("error running day {}: {}", i, e));
+                println!();
+            }
+        }
+    }
+
+    Ok(())
+}