Day 5

src/day1.rs

@@ -1,5 +1,6 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 
+
 #[aoc_generator(day1)]
 pub fn input_generator(input: &str) -> Vec<usize> {
     input

src/day2.rs

@@ -54,22 +54,10 @@ pub fn input_generator(input: &str) -> Vec<Rule> {
 
 #[aoc(day2, part1)]
 pub fn solve_part1(input: &Vec<Rule>) -> usize {
-    let mut total = 0;
-    for rule in input {
-        if rule.is_valid_part1() {
-            total += 1;
-        }
-    }
-    total
+    return input.iter().filter(|v| v.is_valid_part1()).count()
 }
 
 #[aoc(day2, part2)]
 pub fn solve_part2(input: &Vec<Rule>) -> usize {
-    let mut total = 0;
-    for rule in input {
-        if rule.is_valid_part2() {
-            total += 1;
-        }
-    }
-    total
+    return input.iter().filter(|v| v.is_valid_part2()).count()
 }

src/day5.rs

@@ -0,0 +1,87 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+
+#[derive(Debug,Eq,PartialEq)]
+pub enum Direction {
+    Front,
+    Back,
+    Left,
+    Right
+}
+
+#[aoc_generator(day5)]
+pub fn input_generator(input: &str) -> Vec<Vec<Direction>> {
+    input.lines().map(|line| {
+        line.chars().map(|c| {
+            match c {
+                'L' => Direction::Left,
+                'R' => Direction::Right,
+                'F' => Direction::Front,
+                'B' => Direction::Back,
+                other => panic!("Invalid direction: {}",other)
+            }
+        }).collect()
+    }).collect()
+}
+
+pub fn seat_to_pos(seat: &Vec<Direction>) -> (usize,usize) {
+    let mut col_range: (usize, usize) = (0,8);
+    let mut row_range: (usize, usize) = (0,128);
+    for inst in seat {
+        let delta_col = (col_range.1-col_range.0)/2;
+        let delta_row = (row_range.1-row_range.0)/2;
+        match inst {
+            Direction::Back => {
+                row_range.0+=delta_row;
+            },
+            Direction::Front => {
+                row_range.1-=delta_row;
+            },
+            Direction::Left => {
+                col_range.1-=delta_col;
+            },
+            Direction::Right => {
+                col_range.0+=delta_col;
+            },
+        }
+    }
+    if row_range.1-row_range.0 != 1 {
+        panic!("Invalid!");
+    }
+    if col_range.1-col_range.0 != 1 {
+        panic!("Invalid!");
+    }
+    return (col_range.0,row_range.0);
+}
+
+#[aoc(day5, part1)]
+pub fn solve_part1(input: &Vec<Vec<Direction>>) -> usize {
+    let mut max_seat_id: usize = 0;
+    for seat in input {
+        let pos = seat_to_pos(seat);
+        let seat_id = pos.0+pos.1*8;
+        max_seat_id=std::cmp::max(max_seat_id,seat_id);
+    }
+    return max_seat_id;
+}
+
+#[aoc(day5, part2)]
+pub fn solve_part2(input: &Vec<Vec<Direction>>) -> usize {
+    let mut seats = [[false;8];128];
+    for seat in input {
+        let pos = seat_to_pos(seat);
+        seats[pos.1][pos.0]=true;
+    }
+    for id in 0..(8*128) {
+        let mut id=id;
+        let mut v=(false,false,false);
+        v.0=seats[id/8][id%8];
+        id+=1;
+        v.1=seats[id/8][id%8];
+        id+=1;
+        v.2=seats[id/8][id%8];
+        if v==(true,false,true) {
+            return id-1;
+        }
+    }
+    panic!("Something went wrong!");
+}

src/lib.rs

@@ -3,4 +3,5 @@ pub mod day1;
 pub mod day2;
 pub mod day3;
 pub mod day4;
+pub mod day5;
 aoc_lib! { year = 2020 }