[TASK] Solved Day 5

src/day5.rs

@@ -0,0 +1,76 @@
+use super::util;
+
+pub fn solve() {
+
+    let lines = util::read_file("input/day5.txt");
+
+    let seats = lines.iter()
+        .map(|s| Seat::parse(s))
+        .collect::<Vec<Seat>>();
+
+    let part1 = seats.iter()
+        .map(|s| s.seat_id())
+        .max().unwrap_or(0);
+
+    println!("Day 5 Part 1: {}", part1);
+    println!("Day 5 Part 2: {}", solve_part2(&seats));
+
+}
+
+fn solve_part2(seats: &Vec<Seat>) -> u16 {
+    let mut seat_ids = seats.iter()
+        .map(|s| s.seat_id())
+        .collect::<Vec<u16>>();
+    seat_ids.sort();
+    for i in 0..seat_ids.len() {
+        let seat_id = seat_ids[i];
+        // Skip first and last row:
+        if seat_id < 8 || seat_id > (127 << 3) {
+            continue;
+        }
+
+        if seat_id + 1 != seat_ids[i + 1] {
+            return seat_id + 1;
+        }
+    }
+    return 0;
+}
+
+#[derive(Debug)]
+struct Seat {
+    row: u8,
+    col: u8
+}
+
+impl Seat {
+
+    pub fn parse(input: &str) -> Seat {
+
+        return Seat {
+            row: Seat::parse_binary(&input[0..7], 'F', 'B'),
+            col: Seat::parse_binary(&input[7..10], 'L', 'R')
+        }
+    }
+
+    fn parse_binary(src: &str, zero: char, one: char) -> u8 {
+
+        let mut chars = src.chars();
+        let mut res = 0;
+        for i in 0..src.len() {
+            let c = chars.next().unwrap();
+            if c == one {
+                res |= 1 << (src.len() - i - 1)
+            } else if c != zero {
+                eprintln!("Found unknown character: {}", c);
+            }
+        }
+
+        return res;
+    }
+
+    pub fn seat_id(&self) -> u16 {
+
+        return ((self.row as u16) << 3) | (self.col as u16);
+    }
+
+}

src/main.rs

@@ -6,6 +6,7 @@ mod day1;
 mod day2;
 mod day3;
 mod day4;
+mod day5;
 
 fn main() {
 
@@ -20,6 +21,7 @@ fn main() {
             2 => day2::solve(),
             3 => day3::solve(),
             4 => day4::solve(),
+            5 => day5::solve(),
             _ => println!("This day is not yet implemented")
         }
     } else {
@@ -28,6 +30,7 @@ fn main() {
         day2::solve();
         day3::solve();
         day4::solve();
+        day5::solve();
     }
 
     println!("Execution took {} μs", now.elapsed().as_micros());