day 15 pt1

src/bin/15.rs

@@ -0,0 +1,129 @@
+use itertools::Itertools;
+
+advent_of_code::solution!(15);
+
+#[derive(Debug)]
+#[derive(PartialEq)]
+enum TileObject {
+    Empty,
+    Wall,
+    Robot,
+    Box
+}
+
+fn get_tile_object(c: char) -> TileObject {
+    match c {
+        '.' => TileObject::Empty,
+        '#' => TileObject::Wall,
+        '@' => TileObject::Robot,
+        'O' => TileObject::Box,
+        _ => panic!()
+    }
+}
+
+fn get_direction(c: char) -> (isize, isize) {
+    match c {
+        '^' => (-1, 0),
+        'v' => (1, 0),
+        '<' => (0, -1),
+        '>' => (0, 1),
+        _ => panic!()
+    }
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+
+    let mut i = input.lines();
+    let mut grid = i.by_ref().take_while(|l| !l.is_empty()).map(|l| l.chars().map(|c| get_tile_object(c)).collect_vec()).collect_vec();
+
+    let moves = i.by_ref().flat_map(|l| {
+        l.chars().map(|c| get_direction(c)).collect_vec()
+    });
+
+    let mut robot_pos = grid.iter().enumerate().find_map(|(row_idx, row)| {
+        row.iter().enumerate().find_map(|(col_idx, t)| if *t == TileObject::Robot { Some((row_idx, col_idx)) } else { None })
+    }).unwrap();
+
+    grid[robot_pos.0 as usize][robot_pos.1 as usize] = TileObject::Empty;
+
+    // println!("GRID ({}, {})", grid_height, grid_width);
+    // println!("ROBOT ({}, {})", robot_pos.0, robot_pos.1);
+
+    for m in moves {
+        let new_row = (robot_pos.0 as isize + m.0) as usize;
+        let new_col = (robot_pos.1 as isize + m.1) as usize;
+        let next_pos = &grid[new_row][new_col];
+
+        match next_pos {
+            TileObject::Empty => {
+                robot_pos = (new_row, new_col);
+                // print!("M");
+            },
+            TileObject:: Box => {
+                if let Some(next_open_space) = get_next_open_space(&grid, robot_pos, m) {
+                    grid[new_row][new_col] = TileObject::Empty;
+                    grid[next_open_space.0][next_open_space.1] = TileObject::Box;
+
+                    robot_pos = (new_row, new_col);
+                    // print!("~");
+                } else {
+                    // print!("!");
+                }
+            },
+            _ => {
+                // print!("!");
+            }
+        }
+    }
+
+    let calc_score = |row_idx, col_idx| 100 * row_idx + col_idx;
+
+    let gps_score = grid.iter().enumerate().fold(0, |total, (row_idx, row)| {
+        total + row.iter().enumerate().fold(0, |sub_total, (col_idx, tile)| {
+            sub_total + if *tile == TileObject::Box { calc_score(row_idx, col_idx) } else { 0 }
+        })
+    });
+
+
+    Some(gps_score as u32)
+}
+
+pub fn part_two(_input: &str) -> Option<u32> {
+    None
+}
+
+fn get_next_open_space(grid: &[Vec<TileObject>], pos: (usize, usize), m: (isize, isize)) -> Option<(usize, usize)> {
+    let new_row = (pos.0 as isize + m.0) as usize;
+    let new_col = (pos.1 as isize + m.1) as usize;
+    let tile = &grid[new_row][new_col];
+
+    match tile {
+        TileObject::Empty => Some((new_row, new_col)),
+        TileObject::Box => get_next_open_space(grid, (new_row, new_col), m),
+        _ => None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(10092));
+    }
+
+    #[test]
+    fn test_part_one_2() {
+        let result = part_one(&advent_of_code::template::read_file_part("examples", DAY, 2));
+        assert_eq!(result, Some(2028));
+    }
+
+    #[ignore]
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}

src/bin/16.rs

@@ -0,0 +1,26 @@
+advent_of_code::solution!(16);
+
+pub fn part_one(input: &str) -> Option<u32> {
+    None
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}