2023-17: Start implementing part one

input/2023/day_17/input_test.txt

@@ -0,0 +1,13 @@
+2413432311323
+3215453535623
+3255245654254
+3446585845452
+4546657867536
+1438598798454
+4457876987766
+3637877979653
+4654967986887
+4564679986453
+1224686865563
+2546548887735
+4322674655533

src/year_2023/day_17_clumsy_crucible/common.rs

@@ -0,0 +1,7 @@
+#[derive(Debug, Clone, Copy)]
+pub enum Direction {
+    Up,
+    Down,
+    Left,
+    Right,
+}

src/year_2023/day_17_clumsy_crucible/mod.rs

@@ -0,0 +1,25 @@
+pub mod part_one;
+// pub mod part_two;
+pub mod common;
+
+use crate::utils::solution::Solution;
+use crate::utils::input_reader;
+
+pub struct DaySolution ;
+
+
+impl Solution for DaySolution {
+
+    fn input_path(&self) -> &'static str {
+        "input/2023/day_17/input_test.txt"
+    }
+
+    fn part_one(&self) -> String {
+        input_reader::read_input_file(self.input_path(), part_one::part_one)
+    }
+
+    fn part_two(&self) -> String {
+        // input_reader::read_input_file(self.input_path(), part_two::part_two)
+        String::from("Not implemented")
+    }
+}

src/year_2023/day_17_clumsy_crucible/part_one.rs

@@ -0,0 +1,105 @@
+use std::{collections::{HashMap, HashSet}, cmp};
+
+use super::common::Direction;
+
+pub fn part_one(input_lines: Vec<String>) -> String {
+
+    let mut map: Vec<Vec<i32>> = Vec::new();
+    for line in input_lines {
+        let mut row: Vec<i32> = Vec::new();
+        for c in line.chars() {
+            row.push(c.to_digit(10).unwrap() as i32);
+        }
+        map.push(row);
+    }
+
+    let mut cache: HashMap<(i32, i32), i32> = HashMap::new();
+    let current_path: HashSet<(i32, i32)> = HashSet::new();
+
+    let cost = min_cost_path(&map, &mut cache, current_path, Direction::Right, 0, 0, 0) - map[0][0];
+    cost.to_string()
+}
+
+fn min_cost_path(
+    map: &Vec<Vec<i32>>,
+    cache: &mut HashMap<(i32, i32), i32>,
+    mut current_path: HashSet<(i32, i32)>,
+    dir: Direction,
+    step_count: i32,
+    i: i32,
+    j: i32) -> i32 {
+
+    // println!("{}: {} {} {:?}", step_count, i, j, dir);
+
+    if i < 0 || j < 0 || i >= map.len() as i32 || j >= map[0].len() as i32 {
+        return i32::MAX;
+    }
+
+    if step_count >= 3 {
+        return i32::MAX;
+    }
+
+    if current_path.contains(&(i,j)) {
+        return i32::MAX;
+    } else {
+        current_path.insert((i,j));
+    }
+
+    if i == map.len() as i32 - 1 && j == map[0].len() as i32 - 1 {
+        println!("Final path: {:?}", current_path);
+        return map[i as usize][j as usize];
+    }
+
+    if cache.contains_key(&(i,j)) {
+        return *cache.get(&(i,j)).unwrap();
+    }
+
+    let mut cost = map[i as usize][j as usize];
+    let res: i32;
+
+    match dir {
+        Direction::Up => {
+            res = min(
+                min_cost_path(map, cache, current_path.clone(), Direction::Up, step_count + 1, i - 1, j),
+                min_cost_path(map, cache, current_path.clone(), Direction::Left, 0, i, j - 1),
+                min_cost_path(map, cache, current_path.clone(), Direction::Right, 0, i, j + 1)
+            );
+        },
+        Direction::Down => {
+            res = min(
+                min_cost_path(map, cache, current_path.clone(), Direction::Down, step_count + 1, i + 1, j),
+                min_cost_path(map, cache, current_path.clone(), Direction::Left, 0, i, j - 1),
+                min_cost_path(map, cache, current_path.clone(), Direction::Right, 0, i, j + 1)
+            );
+        },
+        Direction::Left => {
+            res = min(
+                min_cost_path(map, cache, current_path.clone(), Direction::Left, step_count + 1, i, j - 1),
+                min_cost_path(map, cache, current_path.clone(), Direction::Up, 0, i - 1, j),
+                min_cost_path(map, cache, current_path.clone(), Direction::Down, 0, i + 1, j)
+            );
+        },
+        Direction::Right => {
+            res = min(
+                min_cost_path(map, cache, current_path.clone(), Direction::Right, step_count + 1, i, j + 1),
+                min_cost_path(map, cache, current_path.clone(), Direction::Up, 0, i - 1, j),
+                min_cost_path(map, cache, current_path.clone(), Direction::Down, 0, i + 1, j)
+            );
+        },        
+    }
+
+    current_path.remove(&(i, j));
+
+    if let Some(new_cost) = cost.checked_add(res) {
+        cost = new_cost;
+    } else {
+        cost = i32::MAX;
+    } 
+    
+    cache.insert((i,j), cost);
+    cost
+}
+
+fn min(a: i32, b: i32 ,c: i32) -> i32 {
+    cmp::min(a, cmp::min(b, c))
+}

src/year_2023/mod.rs

@@ -14,6 +14,7 @@ pub mod day_13_point_of_incidence;
 pub mod day_14_parabolic_reflector_dish;
 pub mod day_15_lens_library;
 pub mod day_16_the_floor_will_be_lava;
+pub mod day_17_clumsy_crucible;
 
 pub fn run(day: &str) {
     let solution: Box<dyn Solution> = match day {
@@ -31,6 +32,7 @@ pub fn run(day: &str) {
         "14" => Box::new(day_14_parabolic_reflector_dish::DaySolution),
         "15" => Box::new(day_15_lens_library::DaySolution),
         "16" => Box::new(day_16_the_floor_will_be_lava::DaySolution),
+        "17" => Box::new(day_17_clumsy_crucible::DaySolution),
         _ => panic!("Invalid day specified"),
     };