From 1e11d80d453687a8f4a50a5744995282aee97279 Mon Sep 17 00:00:00 2001
From: Tyler Beckman <ty@myriation.xyz>
Date: Mon, 23 Dec 2024 23:01:33 -0700
Subject: [PATCH] Day 24 p1

---
 Cargo.toml     |  8 ++++++
 day24/part1.rs | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
 day24/part2.rs | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 141 insertions(+)
 create mode 100644 day24/part1.rs
 create mode 100644 day24/part2.rs

diff --git a/Cargo.toml b/Cargo.toml
index d4ad678..ac98c8d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -67,3 +67,11 @@ path = "day23/part1.rs"
 [[bin]]
 name = "d23p2"
 path = "day23/part2.rs"
+
+[[bin]]
+name = "d24p1"
+path = "day24/part1.rs"
+
+[[bin]]
+name = "d24p2"
+path = "day24/part2.rs"
diff --git a/day24/part1.rs b/day24/part1.rs
new file mode 100644
index 0000000..aa5ad08
--- /dev/null
+++ b/day24/part1.rs
@@ -0,0 +1,66 @@
+use std::collections::HashMap;
+
+use itertools::Itertools;
+
+const INPUT: &str = include_str!("input.txt");
+
+#[derive(Debug)]
+struct Gate<'a> {
+    first: &'a str,
+    second: &'a str,
+    op: Operation
+}
+
+#[repr(u8)]
+#[derive(Debug)]
+enum Operation {
+    And,
+    Or,
+    Xor,
+}
+
+fn solve<'a>(state: &mut HashMap<&'a str, u64>, gates: &'a HashMap<&'a str, Gate>, output: &'a str) -> u64 {
+    state.get(output).map(|&t| t).unwrap_or_else(|| {
+        let gate = &gates[output];
+        let (first_res, second_res) = (solve(state, gates, gate.first), solve(state, gates, gate.second));
+        state.entry(gate.first).or_insert(first_res);
+        state.entry(gate.second).or_insert(second_res);
+        match gate.op {
+            Operation::And => first_res & second_res,
+            Operation::Or => first_res | second_res,
+            Operation::Xor => first_res ^ second_res
+        }
+    })
+}
+
+fn main() {
+    let (state, gates) = INPUT.split("\n\n").collect_tuple().unwrap();
+    let mut state = HashMap::<&str, u64>::from_iter(
+        state
+            .trim()
+            .lines()
+            .map(|l| l.split_once(": ").unwrap())
+            .map(|(wire, value)| (wire, if value == "0" { 0 } else { 1 }))
+    );
+    let gates = HashMap::<&str, Gate>::from_iter(
+        gates
+            .trim()
+            .lines()
+            .map(|l| l.split_once(" -> ").unwrap())
+            .map(|(inputs, output)| (inputs.split(' ').collect_tuple().unwrap(), output))
+            .map(|((first, op, second), output)| (output, Gate { first, second, op: match op {
+                "AND" => Operation::And,
+                "OR" => Operation::Or,
+                "XOR" => Operation::Xor,
+                _ => unreachable!()
+            }}))
+    );
+
+    let mut result = 0u64;
+
+    for (&output, z_value) in gates.keys().filter_map(|k| k.split_once('z').map(|(_, num)| (k, num.parse::<u64>().unwrap()))) {
+        result |= solve(&mut state, &gates, output) << z_value;
+    }
+
+    println!("{result}");
+}
diff --git a/day24/part2.rs b/day24/part2.rs
new file mode 100644
index 0000000..034a183
--- /dev/null
+++ b/day24/part2.rs
@@ -0,0 +1,67 @@
+use std::collections::HashMap;
+
+use itertools::Itertools;
+
+const INPUT: &str = include_str!("input.txt");
+
+#[derive(Debug)]
+struct Gate<'a> {
+    first: &'a str,
+    second: &'a str,
+    op: Operation
+}
+
+#[repr(u8)]
+#[derive(Debug)]
+enum Operation {
+    And,
+    Or,
+    Xor,
+}
+
+fn solve<'a>(state: &mut HashMap<&'a str, u64>, gates: &'a HashMap<&'a str, Gate>, output: &'a str) -> u64 {
+    state.get(output).map(|&t| t).unwrap_or_else(|| {
+        let gate = &gates[output];
+        let (first_res, second_res) = (solve(state, gates, gate.first), solve(state, gates, gate.second));
+        state.entry(gate.first).or_insert(first_res);
+        state.entry(gate.second).or_insert(second_res);
+        match gate.op {
+            Operation::And => first_res & second_res,
+            Operation::Or => first_res | second_res,
+            Operation::Xor => first_res ^ second_res
+        }
+    })
+}
+
+fn main() {
+    let (state, gates) = INPUT.split("\n\n").collect_tuple().unwrap();
+    let mut state = HashMap::<&str, u64>::from_iter(
+        state
+            .trim()
+            .lines()
+            .map(|l| l.split_once(": ").unwrap())
+            .filter(|wire)
+            .map(|(wire, value)| (wire, if value == "0" { 0 } else { 1 }))
+    );
+    let gates = HashMap::<&str, Gate>::from_iter(
+        gates
+            .trim()
+            .lines()
+            .map(|l| l.split_once(" -> ").unwrap())
+            .map(|(inputs, output)| (inputs.split(' ').collect_tuple().unwrap(), output))
+            .map(|((first, op, second), output)| (output, Gate { first, second, op: match op {
+                "AND" => Operation::And,
+                "OR" => Operation::Or,
+                "XOR" => Operation::Xor,
+                _ => unreachable!()
+            }}))
+    );
+
+    let mut result = 0u64;
+
+    for (&output, z_value) in gates.keys().filter_map(|k| k.split_once('z').map(|(_, num)| (k, num.parse::<u64>().unwrap()))) {
+        result |= solve(&mut state, &gates, output) << z_value;
+    }
+
+    println!("{result}");
+}