diff options
Diffstat (limited to 'src/2020/mod.rs')
-rw-r--r-- | src/2020/mod.rs | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/src/2020/mod.rs b/src/2020/mod.rs index 87c213b..27e56fc 100644 --- a/src/2020/mod.rs +++ b/src/2020/mod.rs @@ -4,13 +4,42 @@ use std::io::BufRead as _; pub fn run(day: u8, puzzle: u8) -> anyhow::Result<()> { match (day, puzzle) { (1, 1) => report_repair(), + (1, 2) => report_repair_2(), _ => Err(anyhow::anyhow!("unknown puzzle {}-{}", day, puzzle)), } } fn report_repair() -> anyhow::Result<()> { - let f = std::fs::File::open("data/1-1.txt") - .context("couldn't find data file")?; + let ints = read_ints("data/1.txt")?; + for i in &ints { + for j in &ints { + if i + j == 2020 { + println!("{} * {} = {}", i, j, i * j); + return Ok(()); + } + } + } + Err(anyhow::anyhow!("no numbers summing to 2020 found")) +} + +fn report_repair_2() -> anyhow::Result<()> { + let ints = read_ints("data/1.txt")?; + for i in &ints { + for j in &ints { + for k in &ints { + if i + j + k == 2020 { + println!("{} * {} * {} = {}", i, j, k, i * j * k); + return Ok(()); + } + } + } + } + Err(anyhow::anyhow!("no numbers summing to 2020 found")) +} + +fn read_ints(filename: &str) -> anyhow::Result<Vec<i32>> { + let f = std::fs::File::open(filename) + .with_context(|| format!("couldn't find data file {}", filename))?; let f = std::io::BufReader::new(f); let ints: anyhow::Result<Vec<i32>> = f .lines() @@ -20,14 +49,5 @@ fn report_repair() -> anyhow::Result<()> { .context("failed to parse line into an integer") }) .collect(); - let ints = ints?; - for i in &ints { - for j in &ints { - if i + j == 2020 { - println!("{} + {} = {}", i, j, i * j); - return Ok(()); - } - } - } - Err(anyhow::anyhow!("no numbers summing to 2020 found")) + ints } |