Solved day 8

input/day08.txt

@@ -0,0 +1,50 @@
+............0.......................Bn...........v
+.........0.....................8.........P.....D..
+........M...........Q..0..8...h.......P...........
+......M.A......c...................n..............
+.....C..................A.........................
+.M.AC....................................v........
+........C..........W...w....J........Q...........y
+.....i..............0.....nW.......w.Zv...6.......
+........c....................A.........Pm........D
+.............t.........x..........P....y....m.....
+........................w...x.......F....Z........
+...............Q......x6.......S......Z..O.......J
+..............o.u........x....6.....r.D..M........
+............c...o........u...Y....................
+.........i............9..............g............
+.....................d..WC..8.........J.g.........
+...........X.c...............d...........m........
+....................9.dR...........m......y.......
+.............o.....9.......Y.6.OS...n..........F..
+......i..................a..Q...r.Y.............U.
+.....N......X......u..Ot...a......j......7........
+..........q..X......t.....uH.......j.r..S.7.......
+..........l...t....K.......................J......
+...............9..............OB..................
+...l.R...q..............g.......Y.7..V.......S....
+..........................a.D............V........
+......R.5...v.....W.............KB............U...
+........Kp..F.N...........2.....B..............U..
+..............................d..........h........
+...L...NX...l...R...w..........F...........7......
+..q.L......5.........................j............
+.q.............5.......g..4.......................
+............p...................s2..............Z.
+......L...p...........................s..I........
+........N..............................H..........
+............5......................2.......hV.....
+.............3..........1.......f.a...V...........
+.....K..................................Hz....j...
+.............k.b..G................I.....U........
+.............1......................h.............
+...........p...........L.....s....4T..............
+.b..................G....s.T......I...............
+............................H...........T4........
+...............lk.................T...............
+..i........................1........Iz............
+..............b...........1........G..............
+....b..............G..............................
+........3......k............f..............4......
+3.............k.2.....................z...........
+...........3......................z..f............

input/day08_example.txt

@@ -0,0 +1,12 @@
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............

src/day8.rs

@@ -0,0 +1,139 @@
+use std::collections::HashMap;
+
+use itertools::Itertools;
+
+use crate::{day_solver::DaySolver, util::{Coord, Grid}};
+#[cfg(test)]
+use crate::util::read_file;
+
+pub struct Day8 {
+    map: Grid<char>
+}
+
+impl Day8 {
+
+    pub fn create(input: String) -> Self {
+        
+        return Day8 {
+            map: Grid::parse(input, None)
+        }
+    }
+
+    fn get_antennas_per_frequency(&self) -> HashMap<char, Vec<Coord<usize>>> {
+        let mut frequency_antennas: HashMap<char, Vec<Coord<usize>>> = HashMap::new();
+        for y in 0..self.map.height() {
+            for x in 0..self.map.width {
+                let cur = self.map.get(x, y);
+                let pos: Coord<usize> = Coord::new(x, y);
+                if cur != &'.' {
+                    if let Some(ant_pos) =  frequency_antennas.get_mut(cur) {
+                        ant_pos.push(pos);
+                    } else {
+                        frequency_antennas.insert(cur.to_owned(), vec![pos]);
+                    }
+                }
+
+            }
+        }
+        frequency_antennas
+    }
+
+    fn find_antinodes(&self, antennas: &Vec<Coord<usize>>) -> Vec<Coord<usize>> {
+
+        let mut antinodes = Vec::new();
+
+        for a in antennas {
+            for b in antennas {
+                if a == b {
+                    continue;
+                }
+                let mut a_signed = a.as_signed();
+                let dist = a_signed.sub(&b.as_signed());
+                antinodes.push(a.to_owned());
+                while let Ok(antinode) = TryInto::<Coord<usize>>::try_into(a_signed.add(&dist)) {
+                    if self.map.in_bounds(antinode.x, antinode.y) {
+                        antinodes.push(antinode);
+                    } else {
+                        break;
+                    }
+                    a_signed = antinode.as_signed()
+                }
+            }
+        }
+
+        antinodes
+    }
+}
+
+impl DaySolver for Day8 {
+
+
+    fn solve_part1(&mut self) -> String {
+        
+        let frequency_antennas = self.get_antennas_per_frequency();
+
+        frequency_antennas.iter()
+            .flat_map(|(_, antennas)| {
+                antennas.iter().flat_map(|a|
+                    antennas.iter()
+                        .filter_map(|b| if b.to_owned() == a.to_owned() {
+                            None
+                        } else {
+                            let a_signed = a.as_signed();
+                            let dist = a_signed.sub(&b.as_signed());
+                            Some(a_signed.add(&dist))
+                        })
+                    )
+                })
+            .filter_map::<Coord<usize>, _>(|c| c.try_into().ok())
+            .filter(|c| self.map.in_bounds(c.x, c.y))
+            .unique()
+            // .map(|c| { println!("{:?}", c); c })
+            .count().to_string()
+    }
+
+    fn solve_part2(&mut self) -> String {
+        
+        let frequency_antennas = self.get_antennas_per_frequency();
+
+        let antinodes = frequency_antennas.iter()
+            .flat_map(|(_, antennas)| self.find_antinodes(antennas))
+            .unique()
+            .collect::<Vec<Coord<usize>>>();
+
+        // let mut full_map = self.map.clone();
+        // antinodes.iter().for_each(|n| full_map.set(n.x, n.y, '#'));
+        // full_map.print();
+
+        antinodes
+            .len().to_string()
+    }
+}
+
+#[test]
+fn test_part1() {
+    let mut day = Day8::create(read_file("input/day08_example.txt"));
+    assert_eq!("14", day.solve_part1());
+}
+
+#[test]
+fn test_part1_basic() {
+    let sample = "..........
+..........
+..........
+....a.....
+..........
+.....a....
+..........
+..........
+..........
+..........";
+    let mut day = Day8::create(sample.to_string());
+    assert_eq!("2", day.solve_part1());
+}
+
+#[test]
+fn test_part2() {
+    let mut day = Day8::create(read_file("input/day08_example.txt"));
+    assert_eq!("34", day.solve_part2());
+}

src/main.rs

@@ -8,6 +8,7 @@ use crate::day4::Day4;
 use crate::day5::Day5;
 use crate::day6::Day6;
 use crate::day7::Day7;
+use crate::day8::Day8;
 use crate::day_solver::DaySolver;
 use crate::util::read_file;
 
@@ -20,6 +21,7 @@ mod day4;
 mod day5;
 mod day6;
 mod day7;
+mod day8;
 
 const DEFAULT_BENCHMARK_AMOUNT: u32 = 100;
 
@@ -98,7 +100,7 @@ fn build_day_solver(day: u8, input: String) -> Option<Box<dyn DaySolver>> {
         5 => Some(Box::new(Day5::create(input))),
         6 => Some(Box::new(Day6::create(input))),
         7 => Some(Box::new(Day7::create(input))),
-        // 8 => Some(Box::new(Day8::create(input))),
+        8 => Some(Box::new(Day8::create(input))),
         // 9 => Some(Box::new(Day9::create(input))),
         // 10 => Some(Box::new(Day10::create(input))),
         // 11 => Some(Box::new(Day11::create(input))),

src/util.rs

@@ -2,7 +2,7 @@ use std::fmt::Display;
 use std::fs;
 
 use itertools::Itertools;
-use num::Integer;
+use num::{CheckedSub, Integer};
 
 pub fn read_file(filename: &str) -> String {
     fs::read_to_string(filename)
@@ -148,10 +148,32 @@ impl<T> Coord<T> where T: Sized {
 }
 
 #[allow(dead_code)]
-impl <T> Coord<T> where T: Integer + Copy {
+impl <T> Coord<T> where T: Integer + Copy + CheckedSub {
     pub fn manhattan_dist(&self, other: &Coord<T>) -> T {
         self.x.max(other.x).sub(self.x.min(other.x)) + self.y.max(other.y).sub(self.y.min(other.y))
     }
+
+    pub fn add(&self, other: &Coord<T>) -> Coord<T> {
+        Coord {
+            x: self.x + other.x,
+            y: self.y + other.y
+        }
+    }
+
+    pub fn sub(&self, other: &Coord<T>) -> Coord<T> {
+        Coord {
+            x: self.x - other.x,
+            y: self.y - other.y
+        }
+    }
+    pub fn checked_sub(&self, other: &Coord<T>) -> Option<Coord<T>> {
+        if let Some(x_res) = self.x.checked_sub(&other.x) {
+            if let Some(y_res) = self.y.checked_sub(&other.y) {
+                return Some(Coord::new(x_res, y_res))
+            }
+        }
+        None
+    }
 }
 
 #[allow(dead_code)]
@@ -196,4 +218,21 @@ impl Coord<usize> {
     pub fn add_signed(&self, rhs: Coord<isize>) -> Coord<usize> {
         Coord::new(self.x.wrapping_add_signed(rhs.x), self.y.wrapping_add_signed(rhs.y))
     }
+
+    pub fn as_signed(&self) -> Coord<isize> {
+        Coord::new(self.x.try_into().unwrap(), self.y.try_into().unwrap())
+    }
+}
+
+impl TryFrom<Coord<isize>> for Coord<usize> {
+    fn try_from(value: Coord<isize>) -> Result<Self, Self::Error> {
+        if let Ok(x) = value.x.try_into() {
+            if let Ok(y) = value.y.try_into() {
+                return Ok(Coord::new(x, y))
+            }
+        }
+        Err("It no fit")
+    }
+
+    type Error = &'static str;
 }