Day 3 and cleanup

src/day01.rs

@@ -8,20 +8,19 @@ impl crate::day::Day for Day01 {
     }
 
     fn part1(&self) -> String {
-        let (a, _) = self.0.iter().fold((0, -1), increments);
+        let (a, _) = self.0.iter().copied().fold((0, -1), increments);
         format!("{}", a)
     }
 
     fn part2(&self) -> String {
         let ws = self.0.windows(3).map(|a| a.iter().fold(0, std::ops::Add::add)).collect::<Vec<i32>>();
-        let (a, _) = ws.iter().fold((0, -1), increments);
+        let (a, _) = ws.iter().copied().fold((0, -1), increments);
         format!("{}", a)
     }
 }
 
 
-fn increments((a, b): (i32, i32), c: &i32) -> (i32, i32) {
-    let c = *c;
+fn increments((a, b): (i32, i32), c: i32) -> (i32, i32) {
     if b == -1 {
         (a, c)
     } else if c > b {

src/day03.rs

@@ -0,0 +1,173 @@
+use crate::Day;
+
+pub struct Day03(Vec<Vec<bool>>);
+
+impl Day for Day03 {
+    fn init(content: String) -> Self {
+        let v = content.lines().map(split_lines).collect();
+        Self(v)
+    }
+
+    fn part1(&self) -> String {
+        format!("{}", self.gamma() * self.epsilon())
+    }
+
+    fn part2(&self) -> String {
+        format!("{}", self.ox() * self.co2())
+    }
+}
+
+
+impl Day03 {
+    pub fn gamma_calc(&self) -> Vec<bool> {
+        let mut result = Vec::new();
+        for i in 0..self.0[0].len() {
+            let bit = !matches!(most_common_bit(&self.0.clone(), i), CommonBit::Zero);
+            result.push(bit);
+        }
+        result
+    }
+    pub fn eps_calc(&self) -> Vec<bool> {
+        let mut result = Vec::new();
+        for i in 0..self.0[0].len() {
+            let bit = !matches!(most_common_bit(&self.0.clone(), i), CommonBit::Zero);
+            result.push(!bit);
+        }
+        result
+    }
+
+    pub fn get_oxygen_generator_rating_binary(&self) -> Vec<bool> {
+        let mut working_set = self.0.clone();
+        for i in 0..self.0[0].len() {
+            let common_bit = !matches!(most_common_bit(&working_set.clone(), i), CommonBit::Zero);
+            working_set = working_set
+                .into_iter()
+                .filter(|x| x[i] == common_bit)
+                .collect();
+            if working_set.len() == 1 {
+                break;
+            }
+        }
+        working_set[0].clone()
+    }
+    pub fn get_co2_scrubber_rating_binary(&self) -> Vec<bool> {
+        let mut working_set = self.0.clone();
+        for i in 0..self.0[0].len() {
+            let common_bit = matches!(least_common_bit(&working_set.clone(), i), CommonBit::One);
+            working_set = working_set
+                .into_iter()
+                .filter(|x| x[i] == common_bit)
+                .collect();
+            if working_set.len() == 1 {
+                break;
+            }
+        }
+        working_set[0].clone()
+    }
+
+    pub fn gamma(&self) -> u32 {
+        convert(&self.gamma_calc())
+    }
+    pub fn epsilon(&self) -> u32 {
+        convert(&self.eps_calc())
+    }
+
+    pub fn ox(&self) -> u32 {
+        convert(&self.get_oxygen_generator_rating_binary())
+    }
+    pub fn co2(&self) -> u32 {
+        convert(&self.get_co2_scrubber_rating_binary())
+    }
+}
+
+enum CommonBit {
+    Zero,
+    One,
+    Equal,
+}
+
+fn most_common_bit(set: &[Vec<bool>], bit_position: usize) -> CommonBit {
+    let ones_count = set.iter().fold(
+        0,
+        |ones, code| if code[bit_position] { ones + 1 } else { ones },
+    );
+    let len = (set.len() + 1) / 2;
+    match ones_count.cmp(&len) {
+        std::cmp::Ordering::Less => CommonBit::Zero,
+        std::cmp::Ordering::Equal => CommonBit::Equal,
+        std::cmp::Ordering::Greater => CommonBit::One,
+    }
+}
+
+fn least_common_bit(set: &[Vec<bool>], bit_position: usize) -> CommonBit {
+    let ones_count = set.iter().fold(
+        0,
+        |ones, code| if code[bit_position] { ones + 1 } else { ones },
+    );
+    let len = (set.len() + 1) / 2;
+    match ones_count.cmp(&len) {
+        std::cmp::Ordering::Less => CommonBit::One,
+        std::cmp::Ordering::Equal => CommonBit::Equal,
+        std::cmp::Ordering::Greater => CommonBit::Zero,
+    }
+}
+
+pub fn convert(binary: &[bool]) -> u32 {
+    binary.iter().fold(0, |result, &bit| (result << 1) ^ bit as u32)
+}
+
+
+fn split_lines(content: &str) -> Vec<bool> {
+    content.chars().map(|x| x == '1').collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use std::fs::read_to_string;
+
+    use crate::Day03;
+    use crate::day::Day;
+
+    const INPUT: &str = r"00100
+11110
+10110
+10111
+10101
+01111
+00111
+11100
+10000
+11001
+00010
+01010";
+
+    #[test]
+    fn part1_test() {
+        let t = Day03::init(String::from(INPUT));
+        let p1 = t.part1();
+        assert_eq!("198", p1)
+    }
+
+    #[test]
+    fn part2_test() {
+        let t = Day03::init(String::from(INPUT));
+        let p2 = t.part2();
+        assert_eq!("230", p2)
+    }
+
+    #[test]
+    fn part1_real() {
+        let f = read_to_string("./input/day03").expect("Could not load input");
+        let t = Day03::init(f);
+        let p1 = t.part1();
+        assert_eq!("4118544", p1)
+    }
+
+    #[test]
+    fn part2_real() {
+        let f = read_to_string("./input/day03").expect("Could not load input");
+        let t = Day03::init(f);
+        let p2 = t.part2();
+        assert_eq!("3832770", p2)
+    }
+}

src/main.rs

@@ -3,19 +3,21 @@ use chrono::Datelike;
 use clap::{App, Arg};
 use crate::day01::Day01;
 use crate::day02::Day02;
+use crate::day03::Day03;
 use crate::day::Day;
 
 mod day;
 mod day01;
 mod day02;
+mod day03;
 
 fn load_input(day: &str) -> String {
     read_to_string(format!("./input/day{}", day)).expect("Could not load input")
 }
 
-fn run_day(days: &Vec<Box<dyn Day>>, day: usize) {
+fn run_day(days: &[Box<dyn Day>], day: usize) {
     if let Some(d) = days.get(day - 1) {
-        let day_code = d.clone();
+        let day_code = d;
         println!("Running day {}!", day);
         println!("\tPart 1: {}", d.part1());
         println!("\tPart 2: {}", day_code.part2());
@@ -42,25 +44,26 @@ fn main() {
             .multiple(true))
         .get_matches();
 
-    let days: Vec<Box<dyn Day>> = vec![Box::new(Day01::init(load_input("01"))), Box::new(Day02::init(load_input("02")))];
+    let days: Vec<Box<dyn Day>> = vec![Box::new(Day01::init(load_input("01"))), Box::new(Day02::init(load_input("02"))),
+                                       Box::new(Day03::init(load_input("03")))];
 
     let _verbosity = matches.occurrences_of("v");
     if matches.is_present("all") {
         let l = days.len();
         println!("running {} days!", l);
-        for v in 1..l + 1 {
+        for v in 1..=l {
             run_day(&days, v);
         }
     } else if let Some(d) = matches.values_of("DAY") {
-        let d = d.map(|x| x.parse::<i32>().expect("Did not provide an int!"));
+        let d = d.map(|x| x.parse::<usize>().expect("Did not provide an int!"));
         for v in d {
-            run_day(&days, v as usize);
+            run_day(&days, v);
         }
     } else {
         let v = chrono::Local::now();
         if v.month() != 12 {
-            println!("This was really only meant to be used in december...")
+            println!("This was really only meant to be used in december...");
         }
-        run_day(&days, v.day() as usize)
+        run_day(&days, v.day() as usize);
     }
 }