[CLEANUP] Cleaned up day 16

input/day18_example.txt

@@ -0,0 +1,13 @@
+2,2,2
+1,2,2
+3,2,2
+2,1,2
+2,3,2
+2,2,1
+2,2,3
+2,2,4
+2,2,6
+1,2,5
+3,2,5
+2,1,5
+2,3,5

src/day16.rs

@@ -7,7 +7,7 @@ use super::util;
 pub struct Day16 {
     valves: Vec<Valve>,
     initial_valve_idx: usize,
-    valve_names: Vec<String>
+    // valve_names: Vec<String>
 }
 
 impl Day16 {
@@ -18,23 +18,24 @@ impl Day16 {
 
         // We first map all the valve names to indexes for performance reasons:
         let valve_names = lines.iter()
-            .map(|s| s.split_whitespace().skip(1).next().unwrap().to_string())
+            .map(|s| s.split_whitespace().nth(1).unwrap().to_string())
             .collect::<Vec<String>>();
 
         // Put the input into the day struct
         return Day16 {
-            valves: lines.iter().enumerate().map(|(i, s)| {
+            valves: lines.iter().enumerate().map(|(_, s)| {
-                let mut s_split = s.split(";");
+                let mut s_split = s.split(';');
-                let flow_rate = s_split.next().unwrap().split("rate=").skip(1).next().unwrap().parse::<u32>().unwrap();
+                let flow_rate = s_split.next().unwrap().split("rate=").nth(1).unwrap().parse::<u32>().unwrap();
-                let connections = (&s_split.next().unwrap()["tunnels lead to valves ".len()..].trim()).split(", ")
+                let connections = s_split.next().unwrap()["tunnels lead to valves ".len()..].trim().split(", ")
                     .map(|n| valve_names.iter().position(|nn| n.eq(nn)).unwrap())
                     .collect();
                 Valve {
-                    id: i, flow_rate, connections
+                    // id: i,
+                    flow_rate, connections
                 }
             }).collect(),
             initial_valve_idx: valve_names.iter().position(|n| n == "AA").unwrap(),
-            valve_names
+            // valve_names
         }
     }
 
@@ -46,19 +47,19 @@ impl Day16 {
         open_valves_mask & (1u64 << valve_idx) != 0
     }
 
-    fn is_closed(valve_idx: &usize, open_valves_mask: &u64) -> bool {
+    // fn is_closed(valve_idx: &usize, open_valves_mask: &u64) -> bool {
-        !Self::is_open(valve_idx, open_valves_mask)
+    //     !Self::is_open(valve_idx, open_valves_mask)
-    }
+    // }
-
+    //
-    fn calc_flow_rate(&self, open_valves_mask: &u64) -> u32 {
+    // fn calc_flow_rate(&self, open_valves_mask: &u64) -> u32 {
-        let mut res = 0;
+    //     let mut res = 0;
-        for i in 0..self.valves.len() {
+    //     for i in 0..self.valves.len() {
-            if Self::is_open(&i, open_valves_mask) {
+    //         if Self::is_open(&i, open_valves_mask) {
-                res += self.valves[i].flow_rate
+    //             res += self.valves[i].flow_rate
-            }
+    //         }
-        }
+    //     }
-        res
+    //     res
-    }
+    // }
 
     fn should_valve_be_opened(&self, valve_idx: &usize, open_valves_mask: &u64) -> bool {
         if Self::is_open(valve_idx, open_valves_mask) { false }
@@ -107,8 +108,8 @@ impl Day16 {
 
         // Now we try all combinations of my and elephants options:
         let mut best: u32 = 0;
-        let mut my_best_step = None;
+        // let mut my_best_step = None;
-        let mut elephant_best_step = None;
+        // let mut elephant_best_step = None;
         let next_minutes_left = valve_state.minutes_left - 1;
         for my_option in my_options {
 
@@ -122,7 +123,6 @@ impl Day16 {
                     next_valve_mask_for_me = Self::set_open(&idx, &next_valve_mask_for_me);
                     next_flow_rate_for_me += self.valves[idx].flow_rate
                 }
-                _ => {}
             }
             for elephant_option in &elephant_options {
 
@@ -133,17 +133,16 @@ impl Day16 {
                 match elephant_option {
                     MoveTo(idx) => elephant_next_position = *idx,
                     OpenValve(idx) => {
-                        next_valve_mask = Self::set_open(&idx, &next_valve_mask);
+                        next_valve_mask = Self::set_open(idx, &next_valve_mask);
                         next_flow_rate += self.valves[*idx].flow_rate
                     }
-                    _ => {}
                 }
 
                 let res = self.find_best_option_pt2(ValveStatePt2::new(my_next_position, elephant_next_position, next_valve_mask, next_minutes_left), next_flow_rate, cache);
                 if best == 0 || res.total_flow > best {
                     best = res.total_flow;
-                    my_best_step = Some(my_option);
+                    // my_best_step = Some(my_option);
-                    elephant_best_step = Some(elephant_option.to_owned());
+                    // elephant_best_step = Some(elephant_option.to_owned());
                 }
             }
         }
@@ -173,14 +172,14 @@ impl Day16 {
             // One option is to open the valve at the current position
             let new_open_valves_mask = Self::set_open(&valve_state.my_position, &valve_state.open_valves_mask);
             best_step_result_option = self.find_best_option(ValveState::new(valve_state.my_position, new_open_valves_mask, valve_state.minutes_left - 1), cur_flow_rate + cur_valve.flow_rate, cache);
-            best_step_option = Some(ValveStep::OpenValve(valve_state.my_position));
+            best_step_option = Some(OpenValve(valve_state.my_position));
         }
         // We try and move to an adjacent valve, see if we can be more useful there
         for connection in cur_valve.connections.iter().rev() {
             let next_step_result = self.find_best_option(ValveState::new(connection.to_owned(), valve_state.open_valves_mask, valve_state.minutes_left - 1), cur_flow_rate, cache);
             if best_step_result_option.is_none() || next_step_result.as_ref().unwrap().total_flow > best_step_result_option.as_ref().unwrap().total_flow {
                 best_step_result_option = next_step_result;
-                best_step_option = Some(ValveStep::MoveTo(connection.to_owned()));
+                best_step_option = Some(MoveTo(connection.to_owned()));
             }
         }
 
@@ -242,13 +241,13 @@ impl DaySolver for Day16 {
         let mut cache= HashMap::new();
         let best = self.find_best_option_pt2(ValveStatePt2::new(self.initial_valve_idx, self.initial_valve_idx, 0, 26), 0, &mut cache);
 
-        return best.total_flow.to_string();
+        best.total_flow.to_string()
     }
 }
 
 #[derive(Debug, Clone)]
 struct Valve {
-    id: usize,
+    // id: usize,
     flow_rate: u32,
     connections: Vec<usize>
 }
@@ -299,5 +298,4 @@ struct BestOptionResult {
 enum ValveStep {
     OpenValve(usize),
     MoveTo(usize),
-    None
 }

src/day18.rs

@@ -0,0 +1,205 @@
+use std::collections::{HashSet};
+use crate::day18::VoxelState::{Air, Unknown};
+
+use crate::day_solver::DaySolver;
+
+use super::util;
+
+
+pub struct Day18 {
+    voxels: HashSet<Vec3>
+}
+
+impl Day18 {
+
+    pub fn create() -> Self {
+        // let lines = util::read_file("input/day18_example.txt");
+        let lines = util::read_file("input/day18.txt");
+
+        let voxels = lines.iter().map(|l| {
+            let mut c_iter = l.split(",").map(|c| c.parse().unwrap());
+            Vec3 {
+                x: c_iter.next().unwrap(),
+                y: c_iter.next().unwrap(),
+                z: c_iter.next().unwrap()
+            }
+        }).collect::<HashSet<Vec3>>();
+
+        // Put the input into the day struct
+        return Day18 { voxels }
+    }
+}
+
+impl DaySolver for Day18 {
+
+
+    fn solve_part1(&mut self) -> String {
+        
+        let mut sides = 0;
+        for voxel in &self.voxels {
+            // We just scan all sides if there are voxels there
+            if !self.voxels.contains(&voxel.moved(-1, 0, 0)) { sides += 1 };
+            if !self.voxels.contains(&voxel.moved(1, 0, 0)) { sides += 1 };
+            if !self.voxels.contains(&voxel.moved(0, -1, 0)) { sides += 1 };
+            if !self.voxels.contains(&voxel.moved(0, 1, 0)) { sides += 1 };
+            if !self.voxels.contains(&voxel.moved(0, 0, -1)) { sides += 1 };
+            if !self.voxels.contains(&voxel.moved(0, 0, 1)) { sides += 1 };
+        }
+        return sides.to_string();
+    }
+
+    fn solve_part2(&mut self) -> String {
+
+        // We need to find the cubes that can't be reached 
+        let x_min = self.voxels.iter().map(|v| v.x).min().unwrap();
+        let x_max = self.voxels.iter().map(|v| v.x).max().unwrap();
+        let y_min = self.voxels.iter().map(|v| v.y).min().unwrap();
+        let y_max = self.voxels.iter().map(|v| v.y).max().unwrap();
+        let z_min = self.voxels.iter().map(|v| v.z).min().unwrap();
+        let z_max = self.voxels.iter().map(|v| v.z).max().unwrap();
+
+        let width = (x_max + 1 - x_min) as usize;
+        let height = (y_max + 1 - y_min) as usize;
+        let depth = (z_max + 1 - z_min) as usize;
+
+
+        let mut grid = Grid3D {
+            data: vec![Unknown; width * depth * height],
+            width,
+            height,
+            depth,
+            offset: Vec3 { x: x_min, y: y_min, z: z_min },
+            max: Vec3{ x: x_max, y: y_max, z: z_max}
+        };
+
+        for vox in &self.voxels {
+            grid.set(&vox.x, &vox.y, &vox.z, VoxelState::Rock);
+        }
+
+        let mut queue = Vec::new();
+        // Now we mark all voxels on the edge as air (if they're not rock)
+        for x in grid.offset.x..grid.max.x+1 {
+            for y in grid.offset.y..grid.max.y+1 {
+                queue_if_unknown(&mut grid, &mut queue, &x, &y, &z_min);
+                queue_if_unknown(&mut grid, &mut queue, &x, &y, &z_max);
+            }
+            for z in grid.offset.z..grid.max.z+1 {
+                queue_if_unknown(&mut grid, &mut queue, &x, &y_min, &z);
+                queue_if_unknown(&mut grid, &mut queue, &x, &y_max, &z);
+            }
+        }
+        for z in z_min..z_max + 1 {
+            for y in y_min..y_max + 1 {
+                queue_if_unknown(&mut grid, &mut queue, &x_min, &y, &z);
+                queue_if_unknown(&mut grid, &mut queue, &x_max, &y, &z);
+            }
+        }
+
+        // We search one extra cube around the actual grid, so that the search doesn't get blocked
+        // by rocks hitting the outer edge:
+        queue.push(grid.offset.moved(-1, 0, 0));
+        while let Some(pos) = queue.pop() {
+            // If we got here, it means that "pos" is in air, and we need to check if the neighbors are as well
+            try_pos(&mut grid, &mut queue, &pos, 1, 0, 0);
+            try_pos(&mut grid, &mut queue, &pos, -1, 0, 0);
+            try_pos(&mut grid, &mut queue, &pos, 0, 1, 0);
+            try_pos(&mut grid, &mut queue, &pos, 0, -1, 0);
+            try_pos(&mut grid, &mut queue, &pos, 0, 0, 1);
+            try_pos(&mut grid, &mut queue, &pos, 0, 0, -1);
+        }
+
+        // and finally, we do the same check (basically) as in pt 1:
+        let mut sides = 0;
+        for voxel in &self.voxels {
+            // We just scan all sides if there are voxels there
+            if grid.get(&(voxel.x + 1), &voxel.y, &voxel.z) == &Air { sides += 1 };
+            if grid.get(&(voxel.x - 1), &voxel.y, &voxel.z) == &Air { sides += 1 };
+            if grid.get(&voxel.x, &(voxel.y + 1), &voxel.z) == &Air { sides += 1 };
+            if grid.get(&voxel.x, &(voxel.y - 1), &voxel.z) == &Air { sides += 1 };
+            if grid.get(&voxel.x, &voxel.y, &(voxel.z + 1)) == &Air { sides += 1 };
+            if grid.get(&voxel.x, &voxel.y, &(voxel.z - 1)) == &Air { sides += 1 };
+        }
+        // println!("{:?}", grid.data);
+        // return grid.data.iter().filter(|v| v == &&Unknown).count().to_string();
+        sides.to_string()
+    }
+
+}
+
+fn try_pos(grid: &mut Grid3D, queue: &mut Vec<Vec3>, pos: &Vec3, offset_x: i32, offset_y: i32, offset_z: i32) {
+    let x = pos.x + offset_x;
+    let y =  pos.y + offset_y;
+    let z = pos.z + offset_z;
+    queue_if_unknown(grid, queue, &x, &y, &z);
+}
+
+fn queue_if_unknown(grid: &mut Grid3D, queue: &mut Vec<Vec3>, x: &i32, y: &i32, z: &i32) {
+    if grid.get(x, y, z) == &Unknown {
+        grid.set(x, y, z, Air);
+        queue.push(Vec3::new(*x, *y, *z))
+    }
+}
+
+
+#[derive(Debug, PartialEq, Eq, Hash, Clone)]
+struct Vec3 {
+    x: i32,
+    y: i32,
+    z: i32
+}
+
+impl Vec3 {
+    fn moved(&self, x: i32, y: i32, z: i32) -> Vec3 {
+        Vec3 {
+            x: self.x + x,
+            y: self.y + y,
+            z: self.z + z
+        }
+    }
+
+    fn new(x: i32, y: i32, z: i32) -> Vec3 {
+        return Vec3 {
+            x, y, z
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct Grid3D {
+    data: Vec<VoxelState>,
+    width: usize,
+    height: usize,
+    depth: usize,
+    offset: Vec3,
+    max: Vec3
+}
+
+impl Grid3D {
+    fn set(&mut self, x: &i32, y: &i32, z: &i32, value: VoxelState) {
+
+        if x < &self.offset.x || y < &self.offset.y || z < &self.offset.z {
+            panic!("Invalid position to update the grid: ({}, {}, {})", x, y, z);
+        }
+
+        let coord = self.grid_coord(&x, &y, &z);
+        self.data[coord] = value;
+    }
+
+    fn get(&self, x: &i32, y: &i32, z: &i32) -> &VoxelState {
+        if x < &self.offset.x || y < &self.offset.y || z < &self.offset.z || 
+            x > &self.max.x || y > &self.max.y || z > &self.max.z {
+                &VoxelState::Air
+            } else {
+                &self.data[self.grid_coord(x, y, z)]
+            }
+    }
+
+    fn grid_coord(&self, x: &i32, y: &i32, z: &i32) -> usize {
+        (x - self.offset.x) as usize + ((y - self.offset.y) as usize * self.width) + ((z - self.offset.z) as usize * self.width * self.height)
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+enum VoxelState {
+    Air, Rock, Unknown
+}

src/main.rs

@@ -18,6 +18,7 @@ use crate::day14::Day14;
 use crate::day15::Day15;
 use crate::day16::Day16;
 use crate::day17::Day17;
+use crate::day18::Day18;
 use crate::day_solver::DaySolver;
 
 mod util;
@@ -39,6 +40,7 @@ mod day14;
 mod day15;
 mod day16;
 mod day17;
+mod day18;
 
 const MAX_DAY: u8 = 17;
 const DEFAULT_BENCHMARK_AMOUNT: u32 = 100;
@@ -121,6 +123,7 @@ fn build_day_solver(day: u8) -> Option<Box<dyn DaySolver>> {
         15 => Some(Box::new(Day15::create())),
         16 => Some(Box::new(Day16::create())),
         17 => Some(Box::new(Day17::create())),
+        18 => Some(Box::new(Day18::create())),
         _ => None
     }
 }