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authorcos <cos>2020-12-06 09:05:40 +0100
committercos <cos>2020-12-06 10:10:04 +0100
commita0b89c75d8429cdfbff99c02e9fc8d332641e189 (patch)
tree6a766ec7d24f6b8fe347a67e1d742917eca2c00c /2020
parent59290646080f5f1af417ba276355bd4fb7c49c20 (diff)
downloadadventofcode-a0b89c75d8429cdfbff99c02e9fc8d332641e189.zip
Add day06, 2020
Diffstat (limited to '2020')
-rw-r--r--2020/rust/Cargo.toml2
-rw-r--r--2020/rust/day06/Cargo.toml10
-rw-r--r--2020/rust/day06/src/main.rs92
3 files changed, 103 insertions, 1 deletions
diff --git a/2020/rust/Cargo.toml b/2020/rust/Cargo.toml
index 9c02f59..7c6ce52 100644
--- a/2020/rust/Cargo.toml
+++ b/2020/rust/Cargo.toml
@@ -6,7 +6,7 @@ members = [
"day03",
"day04",
"day05",
-# "day06",
+ "day06",
# "day07",
# "day08",
# "day09",
diff --git a/2020/rust/day06/Cargo.toml b/2020/rust/day06/Cargo.toml
new file mode 100644
index 0000000..0a1e5f4
--- /dev/null
+++ b/2020/rust/day06/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "day06"
+version = "0.1.0"
+authors = ["cos <cos>"]
+edition = "2018"
+
+[dependencies]
+aoc = { path = "../aoc" }
+anyhow = "1.0"
+thiserror = "1.0"
diff --git a/2020/rust/day06/src/main.rs b/2020/rust/day06/src/main.rs
new file mode 100644
index 0000000..948276a
--- /dev/null
+++ b/2020/rust/day06/src/main.rs
@@ -0,0 +1,92 @@
+use anyhow::Result;
+use std::collections::HashSet;
+use std::env::args;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::Path;
+
+fn read_input<T: AsRef<Path>>(filename: T) -> Result<Vec<Vec<String>>> {
+ let f = File::open(filename)?;
+ let reader = BufReader::new(f);
+ let mut group = vec![];
+ let mut groups = vec![];
+
+ for line in reader.lines() {
+ let line = line?;
+ if line.is_empty() {
+ groups.push(group);
+ group = vec![];
+ continue;
+ }
+ group.push(line);
+ }
+ groups.push(group);
+
+ Ok(groups)
+}
+
+fn part1(input: &[Vec<String>]) -> Option<usize> {
+ let mut groups = vec![];
+ for group in input {
+ let mut set = HashSet::new();
+ for form in group.iter() {
+ for answer in form.clone().drain(..) {
+ set.insert(answer);
+ }
+ }
+ groups.push(set);
+ }
+ Some(groups.iter().map(|g| g.len()).sum())
+}
+
+fn part2(input: &[Vec<String>]) -> Option<usize> {
+ let mut groups = vec![];
+ for group in input {
+ let sets: Vec<_> = group.iter().map(|form| {
+ let mut set = HashSet::new();
+ for answer in form.clone().drain(..) {
+ set.insert(answer);
+ }
+ set
+ }).collect();
+ let combined: HashSet<_> = match sets.get(0) {
+ Some(first) => sets.iter()
+ .fold(first.clone(), |a, s| s.intersection(&a).cloned().collect()),
+ None => return None,
+ };
+
+ groups.push(combined);
+ }
+ Some(groups.iter().map(|g| g.len()).sum())
+}
+
+fn main() {
+ let (do_part_1, do_part_2) = aoc::do_parts();
+
+ let filename = match args().nth(1) {
+ Some(f) => f,
+ None => {
+ eprintln!("Missing input filename");
+ std::process::exit(1);
+ },
+ };
+ match read_input(filename) {
+ Ok(input) => {
+ if do_part_1 {
+ match part1(&input) {
+ Some(solution) =>
+ println!("Part1, sum of all groups combined yes answers: {}", solution),
+ None => eprintln!("Part1, no soluton found"),
+ }
+ }
+ if do_part_2 {
+ match part2(&input) {
+ Some(solution) =>
+ println!("Part2, sum of all groups common yes answers: {}", solution),
+ None => eprintln!("Part2, no soluton found"),
+ }
+ }
+ },
+ Err(err) => eprintln!("Could not read input: {}", err),
+ }
+}