day_11: part 1 done

src/advent_of_code/mod.rs

@@ -7,9 +7,10 @@
 // mod sat_07;
 // mod sun_08;
 // mod mon_09;
-mod tue_10;
+// mod tue_10;
 mod types;
 mod utils;
+mod wed_11;
 
 use types::*;
 
@@ -78,8 +79,15 @@ pub fn historian_hysteria() {
     // println!("The disk checksum is {}", disk_checksum);
 
     // Tuesday 10
-    let (trailhead_score, full_trailhead_score) =
-        tue_10::hoof_it("./assets/day_10_trail_map_input");
-    println!("The trail head sum score is {}", trailhead_score);
-    println!("The full trail head sum score is {}", full_trailhead_score);
+    // let (trailhead_score, full_trailhead_score) =
+    //     tue_10::hoof_it("./assets/day_10_trail_map_input");
+    // println!("The trail head sum score is {}", trailhead_score);
+    // println!("The full trail head sum score is {}", full_trailhead_score);
+    let blink_count: usize = 25;
+    let stone_count =
+        wed_11::plutonian_pebbles("./assets/day_11_stone_arrangement_input", blink_count);
+    println!(
+        "The total of stones after {} is {}",
+        blink_count, stone_count
+    );
 }

src/advent_of_code/types.rs

@@ -81,3 +81,8 @@ pub type DiskChecksum = usize;
 pub type TrailScore = usize;
 pub type TrailPosition = usize;
 pub type TrailMap = Vec<Vec<TrailPosition>>;
+
+// Plutonian Pebbles
+pub type StoneCount = usize;
+pub type Stone = usize;
+pub type StoneList = Vec<Stone>;

src/advent_of_code/utils.rs

@@ -206,6 +206,18 @@ pub fn read_trail_map_input(input: &str) -> TrailMap {
     trail_map
 }
 
+pub fn read_stone_arrangement(input: &str) -> StoneList {
+    let mut stone_list: StoneList = vec![];
+
+    for line in read_to_string(input).unwrap().lines() {
+        for number in line.split(" ") {
+            stone_list.push(number.parse::<Stone>().unwrap());
+        }
+    }
+
+    stone_list
+}
+
 pub fn calc_distance<T>(num_1: T, num_2: T) -> T
 where
     T: PartialOrd + Sub<Output = T>,

src/advent_of_code/wed_11.rs

@@ -0,0 +1,53 @@
+use super::*;
+
+pub fn plutonian_pebbles(input: &str, blink_count: usize) -> StoneCount {
+    let stone_list = utils::read_stone_arrangement(input);
+
+    let stone_list = apply_rules(stone_list, blink_count);
+
+    stone_list.len()
+}
+
+fn apply_rules(stone_list: StoneList, blink_count: usize) -> StoneList {
+    let mut new_stone_list = stone_list.clone();
+
+    for _ in 0..blink_count {
+        new_stone_list = blink(new_stone_list);
+    }
+
+    new_stone_list
+}
+
+fn blink(stone_list: StoneList) -> StoneList {
+    let mut new_stone_list: StoneList = vec![];
+
+    const STONE_MULTIPLIER: usize = 2024;
+    for stone in stone_list {
+        match stone {
+            0 => {
+                new_stone_list.push(1);
+            }
+            stone if stone.to_string().len() % 2 == 0 => {
+                let (left, right) = split_num(stone);
+                new_stone_list.push(left);
+                new_stone_list.push(right);
+            }
+            _ => {
+                new_stone_list.push(stone * STONE_MULTIPLIER);
+            }
+        }
+    }
+
+    new_stone_list
+}
+
+fn split_num(num: Stone) -> (Stone, Stone) {
+    let split_index = num.to_string().len() / 2;
+    let binding = num.to_string();
+    let (first, second) = binding.split_at(split_index);
+
+    (
+        first.parse::<Stone>().unwrap(),
+        second.parse::<Stone>().unwrap(),
+    )
+}