d08

res/08/example

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

res/08/input

@@ -0,0 +1,50 @@
+.E..........m..0N.........f.......................
+........N........P0...............................
+.......j..................................F.......
+........1j............P........................C..
+...........................3..K......f..........E.
+...........V...y...0.....................F........
+1.......j.....P....y.N.......................F....
+....................m...................C.........
+..L......P....p..................w.m..............
+............E......p..AU........8......f..........
+..............C...............w....d..............
+j1...............E..........3.........f........w..
+.................p...A..........3.................
+.................3..p........KU...w..r..F.........
+7.........y........8.......................r......
+........y..u......K...............................
+...1..................8....C...K..................
+...........h.......................6..............
+......................U.........A.r..t........6...
+...........5.........8..c.........................
+.................U................t...............
+.....L...O...................t.............d......
+.........7........................................
+......L..H...c.....9....t.................6.......
+...........................c.M..................4.
+.....R..7...O.....................................
+.......................9......................d...
+..................................................
+.........L..9...R..........................6c.....
+..M.....T.5.................................d.....
+.......5OR...................T....................
+.......D......o.........v...................r.....
+...u....o.........5...............................
+.......WR.....Y...........................e...4...
+T............O......M..................4..a.......
+.Y...................M............................
+........W..D...............oh............e........
+.......7......Do...................A...e.......4..
+.W...Y..D........................h...v..........e.
+..........V.....9.l.......h.......a.........n..v..
+.......................H.....a2...................
+..................................................
+...V............Y....J..H2................vn......
+..............................H2.................n
+................V..........l...........k..........
+.T..u........................J...ak...............
+..................J.....l.........................
+.................l................................
+......u.........................................n.
+......................J..k............2...........

src/days/d08.rs

@@ -0,0 +1,106 @@
+use std::collections::{HashMap, HashSet};
+
+use std::fs;
+
+pub fn solve() {
+    let path = "res/08/input";
+
+    let contents = fs::read_to_string(path).expect("Something went wrong reading the file");
+
+    let mut antennas: HashMap<char, Vec<(isize, isize)>> = HashMap::new();
+
+    let rows = contents.lines().count();
+    let cols = contents.lines().next().unwrap().chars().count();
+
+    for (i, line) in contents.lines().enumerate() {
+        for (j, c) in line.chars().enumerate() {
+            match c {
+                '.' => {}
+                _ => {
+                    let entry = antennas.entry(c).or_insert(Vec::new());
+                    entry.push((i as isize, j as isize));
+                }
+            }
+        }
+    }
+
+    let mut antinodes: HashSet<(isize, isize)> = HashSet::new();
+
+    antennas.iter().for_each(|(_, v)| {
+        v.iter().enumerate().for_each(|(i, (x1, y1))| {
+            v.iter().skip(i + 1).for_each(|(x2, y2)| {
+                if x1 == x2 && y1 == y2 {
+                    return;
+                }
+                let (a_x1, a_y1) = (x1 + (x1 - x2), y1 + (y1 - y2));
+                let (a_x2, a_y2) = (x2 + (x2 - x1), y2 + (y2 - y1));
+
+                if a_x1 >= 0 && a_y1 >= 0 && a_x1 < rows as isize && a_y1 < cols as isize {
+                    antinodes.insert((a_x1, a_y1));
+                }
+                if a_x2 >= 0 && a_y2 >= 0 && a_x2 < rows as isize && a_y2 < cols as isize {
+                    antinodes.insert((a_x2, a_y2));
+                }
+            })
+        })
+    });
+
+    let result = antinodes.len();
+
+    println!("Result 1: {}", result);
+
+    let mut antinodes: HashSet<(isize, isize)> = HashSet::new();
+
+    antennas.iter().for_each(|(_, v)| {
+        v.iter().enumerate().for_each(|(i, (x1, y1))| {
+            v.iter().skip(i + 1).for_each(|(x2, y2)| {
+                if x1 == x2 && y1 == y2 {
+                    return;
+                }
+
+                let ax1_diff = x1 - x2;
+                let ay1_diff = y1 - y2;
+                let a1_gcd = gcd(ax1_diff, ay1_diff);
+
+                let mut cnt = 0;
+                loop {
+                    let (ax, ay) = (x1 + ax1_diff * cnt / a1_gcd, y1 + ay1_diff * cnt / a1_gcd);
+                    if ax < 0 || ay < 0 || ax >= rows as isize || ay >= cols as isize {
+                        break;
+                    }
+                    antinodes.insert((ax, ay));
+                    cnt += 1;
+                }
+
+                let ax2_diff = x2 - x1;
+                let ay2_diff = y2 - y1;
+                let a2_gcd = gcd(ax2_diff, ay2_diff);
+
+                cnt = 0;
+                loop {
+                    let (ax, ay) = (x2 + ax2_diff * cnt / a2_gcd, y2 + ay2_diff * cnt / a2_gcd);
+                    if ax < 0 || ay < 0 || ax >= rows as isize || ay >= cols as isize {
+                        break;
+                    }
+                    antinodes.insert((ax, ay));
+                    cnt += 1;
+                }
+            })
+        })
+    });
+
+    let result = antinodes.len();
+
+    println!("Result 2: {}", result);
+}
+
+fn gcd(mut a: isize, mut b: isize) -> isize {
+    a = a.abs();
+    b = b.abs();
+    while b != 0 {
+        let temp = b;
+        b = a % b;
+        a = temp;
+    }
+    a
+}

src/main.rs

@@ -4,12 +4,45 @@ extern crate scan_fmt;
 use std::time::Instant;
 
 fn main() {
-    //days::d07::solve()
+    if std::env::args().len() > 1 {
-    _all_days()
+        if let Some(day) = std::env::args().nth(1) {
+            match day.as_str() {
+                "all" => all_days(),
+                "1" => days::d01::solve(),
+                "2" => days::d02::solve(),
+                "3" => days::d03::solve(),
+                "4" => days::d04::solve(),
+                "5" => days::d05::solve(),
+                "6" => days::d06::solve(),
+                "7" => days::d07::solve(),
+                "8" => days::d08::solve(),
+                //"9" => days::d09::solve(),
+                //"10" => days::d10::solve(),
+                //"11" => days::d11::solve(),
+                //"12" => days::d12::solve(),
+                //"13" => days::d13::solve(),
+                //"14" => days::d14::solve(),
+                //"15" => days::d15::solve(),
+                //"16" => days::d16::solve(),
+                //"17" => days::d17::solve(),
+                //"18" => days::d18::solve(),
+                //"19" => days::d19::solve(),
+                //"20" => days::d20::solve(),
+                //"21" => days::d21::solve(),
+                //"22" => days::d22::solve(),
+                //"23" => days::d23::solve(),
+                //"24" => days::d24::solve(),
+                //"25" => days::d25::solve(),
+                _ => println!("Day not implemented"),
+            }
+        }
+    } else {
+        all_days();
+    }
 }
 
-#[allow(unreachable_code, unused)]
+#[allow(unused)]
-fn _all_days() {
+fn all_days() {
     let start = Instant::now();
     let mut time = start.clone();
 
@@ -41,11 +74,11 @@ fn _all_days() {
     days::d07::solve();
     time = _print_elapsed(time);
 
-    /*
     println!("\nDay 8");
     days::d08::solve();
     time = _print_elapsed(time);
 
+    /*
     println!("\nDay 9");
     days::d09::solve();
     time = _print_elapsed(time);