Day 15

src/day_15_1/mod.rs

+pub fn solve_from_str(input: &str) -> u32 {
+    input
+        .split(",")
+        .map(|string| {
+            string
+                .chars()
+                .fold(0, |acc, char| (acc + char as u32) * 17 % 256)
+        })
+        .sum()
+}

src/day_15_2/mod.rs

+pub fn solve_from_str(input: &str) -> usize {
+    let mut hashmap: Vec<Vec<(&str, usize)>> = Vec::new();
+
+    for i in 0..256 {
+        hashmap.push(Vec::new());
+    }
+
+    for instruction in input.split(",") {
+        if instruction.contains("=") {
+            let mut data = instruction.split("=");
+            let label = data.next().unwrap();
+            let focal_length = str::parse(data.next().unwrap()).unwrap();
+
+            let lensbox = &mut hashmap[hash(label)];
+
+            let index = lensbox.iter().enumerate().find_map(|(index, lens)| {
+                if lens.0.eq(label) {
+                    Some(index)
+                } else {
+                    None
+                }
+            });
+            if let Some(index) = index {
+                lensbox[index] = (label, focal_length);
+            } else {
+                lensbox.push((label, focal_length));
+            }
+        } else if instruction.contains("-") {
+            let mut data = instruction.split("-");
+            let label = data.next().unwrap();
+
+            let lensbox = &mut hashmap[hash(label)];
+
+            let index = lensbox.iter().enumerate().find_map(|(index, lens)| {
+                if lens.0.eq(label) {
+                    Some(index)
+                } else {
+                    None
+                }
+            });
+
+            if let Some(index) = index {
+                lensbox.remove(index);
+            }
+        } else {
+            panic!();
+        }
+    }
+
+    hashmap
+        .iter()
+        .enumerate()
+        .map(|(boxindex, lensbox)| {
+            lensbox
+                .iter()
+                .enumerate()
+                .map(|(lensindex, lens)| (boxindex + 1) * (lensindex + 1) * lens.1)
+                .sum::<usize>()
+        })
+        .sum()
+}
+
+fn hash(input: &str) -> usize {
+    input
+        .chars()
+        .fold(0, |acc, char| (acc + char as usize) * 17 % 256)
+}

src/main.rs

@@ -4,6 +4,11 @@ mod day_11_1;
 mod day_11_2;
 mod day_12_1;
 mod day_12_2;
+mod day_13_1;
+mod day_13_2;
+mod day_14_1;
+mod day_15_1;
+mod day_15_2;
 mod day_1_1;
 mod day_1_2;
 mod day_2_1;