From 79da3ab4aa2c120aeb51cba40c0cc2d7af16d798 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Zo=C3=A9=20Cassiop=C3=A9e=20Gauthier?= Date: Fri, 3 Dec 2021 17:21:47 -0500 Subject: [PATCH] Day 3 clean-up --- src/day3.rs | 182 +++++++++++++++++++++++++++++----------------------- 1 file changed, 102 insertions(+), 80 deletions(-) diff --git a/src/day3.rs b/src/day3.rs index e5966d5..83808d4 100644 --- a/src/day3.rs +++ b/src/day3.rs @@ -1,94 +1,115 @@ use std::io::{self, BufRead}; -fn most_common_bits(report: &Vec) -> String { - (0..12) - .map(|i| { - let counts = report - .iter() - .fold((0, 0), |acc, x| match x.chars().nth(i).unwrap() { - '0' => (acc.0 + 1, acc.1), - '1' => (acc.0, acc.1 + 1), - _ => acc, - }); - if counts.0 > counts.1 { - '0' - } else { - '1' - } - }) - .collect() +struct Diagnostics { + report: Vec, } -fn most_common_value(report: Vec, n: usize) -> Option { - (0..n) - .fold(report, |r, i| { - if r.len() > 1 { - let counts = r - .iter() - .fold((0, 0), |acc, x| match x.chars().nth(i).unwrap() { - '0' => (acc.0 + 1, acc.1), - '1' => (acc.0, acc.1 + 1), - _ => acc, - }); - r.iter() - .filter(|x| match x.chars().nth(i).unwrap() { - '0' if counts.0 > counts.1 => true, - '1' if counts.0 <= counts.1 => true, - _ => false, - }) - .cloned() - .collect() - } else { - r - } - }) - .first() - .cloned() -} +impl Diagnostics { + fn gamma_rate(&self) -> u32 { + u32::from_str_radix(&self.most_common_bits(), 2).unwrap() + } -fn least_common_value(report: Vec) -> Option { - (0..12) - .fold(report, |r, i| { - if r.len() > 1 { - let counts = r - .iter() - .fold((0, 0), |acc, x| match x.chars().nth(i).unwrap() { - '0' => (acc.0 + 1, acc.1), - '1' => (acc.0, acc.1 + 1), - _ => acc, - }); - r.iter() - .filter(|x| match x.chars().nth(i).unwrap() { - '0' if counts.0 <= counts.1 => true, - '1' if counts.0 > counts.1 => true, - _ => false, - }) - .cloned() - .collect() - } else { - r - } - }) - .first() - .cloned() + fn epsilon_rate(&self) -> u32 { + 0xfff ^ self.gamma_rate() + } + + fn oxygen_generator_rating(&self) -> u32 { + u32::from_str_radix(&self.most_common_value(), 2).unwrap() + } + + fn co2_scrubber_rating(&self) -> u32 { + u32::from_str_radix(&self.least_common_value(), 2).unwrap() + } + + fn count_bit(&self, values: &Vec, bit: usize) -> (usize, usize) { + values + .iter() + .fold((0, 0), |acc, x| match x.chars().nth(bit).unwrap() { + '0' => (acc.0 + 1, acc.1), + '1' => (acc.0, acc.1 + 1), + _ => acc, + }) + } + + fn most_common_bits(&self) -> String { + (0..N) + .map(|i| { + let (zeros, ones) = self.count_bit(&self.report, i); + if zeros > ones { + '0' + } else { + '1' + } + }) + .collect() + } + + fn filter_values( + &self, + values: Vec, + bit: usize, + predicate: impl Fn(usize, usize) -> bool, + ) -> Vec { + if values.len() <= 1 { + return values; + } + let (zeros, ones) = self.count_bit(&values, bit); + values + .iter() + .filter(|x| match x.chars().nth(bit).unwrap() { + '0' if !predicate(zeros, ones) => true, + '1' if predicate(zeros, ones) => true, + _ => false, + }) + .cloned() + .collect() + } + + fn most_common_value(&self) -> String { + (0..N) + .fold(self.report.clone(), |r, i| { + self.filter_values(r, i, |zeros, ones| ones >= zeros) + }) + .first() + .unwrap() + .clone() + } + + fn least_common_value(&self) -> String { + (0..N) + .fold(self.report.clone(), |r, i| { + self.filter_values(r, i, |zeros, ones| ones < zeros) + }) + .first() + .unwrap() + .clone() + } } fn main() { const INPUT: &'static str = include_str!("../inputs/day3.txt"); let report: Vec = io::Cursor::new(INPUT).lines().map(|l| l.unwrap()).collect(); - let gamma_rate = u32::from_str_radix(&most_common_bits(&report), 2).unwrap(); - let epsilon_rate = 0xfff ^ gamma_rate; - println!("gamma rate {} epsilon rate {}", gamma_rate, epsilon_rate); - println!("solution {}", gamma_rate * epsilon_rate); + let diagnostics = Diagnostics::<12> { report: report }; - let oxygen_generator_rating = - u32::from_str_radix(&most_common_value(report.clone(), 12).unwrap(), 2).unwrap(); - println!("oxygen generator rating {}", oxygen_generator_rating); + println!( + "gamma rate {} epsilon rate {}", + diagnostics.gamma_rate(), + diagnostics.epsilon_rate() + ); + println!( + "solution {}", + diagnostics.gamma_rate() * diagnostics.epsilon_rate() + ); - let co2_scrubber_rating = u32::from_str_radix(&least_common_value(report).unwrap(), 2).unwrap(); - println!("CO2 scrubber rating {}", co2_scrubber_rating); - - println!("solution {}", oxygen_generator_rating * co2_scrubber_rating); + println!( + "oxygen generator rating {} CO2 scrubber rating {}", + diagnostics.oxygen_generator_rating(), + diagnostics.co2_scrubber_rating() + ); + println!( + "solution {}", + diagnostics.oxygen_generator_rating() * diagnostics.co2_scrubber_rating() + ); } #[test] @@ -107,5 +128,6 @@ fn oxygen_generator_rating() { "00010".to_string(), "01010".to_string(), ]; - assert_eq!(most_common_value(report, 5).unwrap(), "10111"); + let diagnostics = Diagnostics::<5> { report: report }; + assert_eq!(diagnostics.most_common_value(), "10111"); }