1 files changed, 94 insertions, 0 deletions
diff --git a/2015/rs/src/seven.rs b/2015/rs/src/seven.rs
new file mode 100644
index 0000000..7d44f0e
--- /dev/null
+++ b/2015/rs/src/seven.rs
@@ -0,0 +1,94 @@
+use std::collections::HashMap;
+
+static INPUT: &[u8] = include_bytes!("seven.txt");
+
+#[derive(Debug, Copy, Clone)]
+enum WireOrLiteral {
+  Wire([u8; 2]),
+  Literal(u16)
+}
+
+#[derive(Debug, Copy, Clone)]
+enum Connection {
+  Direct(WireOrLiteral),
+  Not   (WireOrLiteral),
+  And   (WireOrLiteral, WireOrLiteral),
+  Or    (WireOrLiteral, WireOrLiteral),
+  LShift(WireOrLiteral, WireOrLiteral),
+  RShift(WireOrLiteral, WireOrLiteral),
+}
+
+#[derive(Debug, Copy, Clone)]
+enum Cache {
+  Cached(u16),
+  Uncached(Connection)
+}
+
+fn main() {
+  let valueified = INPUT
+    .split(|b| *b == b'\n').filter(|b| !b.is_empty())
+    .map(|line| {
+      let mut bits = line.split(|b| *b == b'-');
+      let (rhs, lhs) = (bits.next().unwrap().strip_suffix(b" ").unwrap(), bits.next().unwrap().strip_prefix(b"> ").unwrap());
+      let mut cmdbits = rhs.split(|b| *b == b' ');
+      let cmdbits = (cmdbits.next().unwrap(), cmdbits.next().unwrap_or(&[]), cmdbits.next().unwrap_or(&[]));
+
+      let connection = match cmdbits {
+        (wol, &[], &[]) => Connection::Direct(parse_wol(wol)),
+        (b"NOT", wol, &[]) => Connection::Not(parse_wol(wol)),
+        (wol1, b"AND", wol2) => Connection::And(parse_wol(wol1), parse_wol(wol2)),
+        (wol1, b"OR", wol2) => Connection::Or(parse_wol(wol1), parse_wol(wol2)),
+        (wol1, b"LSHIFT", wol2) => Connection::LShift(parse_wol(wol1), parse_wol(wol2)),
+        (wol1, b"RSHIFT", wol2) => Connection::RShift(parse_wol(wol1), parse_wol(wol2)),
+        _ => unreachable!()
+      };
+
+      let wire = [lhs[0], *lhs.get(1).unwrap_or(&0)];
+
+      (wire, Cache::Uncached(connection))
+    })
+    .collect::<HashMap<[u8; 2], Cache>>();
+
+  let mut part1 = valueified.clone();
+  let a_val = walk(*b"a\0", &mut part1);
+  println!("a: {a_val}");
+
+
+  let mut part2 = valueified.clone();
+  part2.insert(*b"b\0", Cache::Uncached(Connection::Direct(WireOrLiteral::Literal(a_val))));
+  let a_val_2 = walk(*b"a\0", &mut part2);
+  println!("a with b={a_val}: {a_val_2}");
+}
+
+fn parse_wol(bytes: &[u8]) -> WireOrLiteral {
+  if bytes.iter().all(u8::is_ascii_digit) {
+    WireOrLiteral::Literal(std::str::from_utf8(bytes).unwrap().parse().unwrap())
+  } else {
+    WireOrLiteral::Wire([bytes[0], *bytes.get(1).unwrap_or(&0)])
+  }
+}
+
+fn walk(key: [u8; 2], map: &mut HashMap<[u8; 2], Cache>) -> u16 {
+  match map[&key] {
+    Cache::Cached(val) => val,
+    Cache::Uncached(conn) => {
+      let val = match conn {
+        Connection::Direct(wol) => get_wol(wol, map),
+        Connection::Not(wol) => !get_wol(wol, map),
+        Connection::And(wol1, wol2) => get_wol(wol1, map) & get_wol(wol2, map),
+        Connection::Or(wol1, wol2) => get_wol(wol1, map) | get_wol(wol2, map),
+        Connection::LShift(wol1, wol2) => get_wol(wol1, map) << get_wol(wol2, map),
+        Connection::RShift(wol1, wol2) => get_wol(wol1, map) >> get_wol(wol2, map)
+      };
+      map.insert(key, Cache::Cached(val));
+      val
+    }
+  }
+}
+
+fn get_wol(wol: WireOrLiteral, map: &mut HashMap<[u8; 2], Cache>) -> u16 {
+  match wol {
+    WireOrLiteral::Wire(wire) => walk(wire, map),
+    WireOrLiteral::Literal(literal) => literal
+  }
+}