d23p1

day23/d23p1.swift

@@ -0,0 +1,43 @@
+import Foundation
+
+typealias Network = [String: Set<String>]
+
+func readInput(_ filePath: String) throws -> Network {
+    var map: Network = [:]
+    try String(contentsOfFile: filePath, encoding: .ascii)
+        .split(separator: "\n").map { $0.split(separator: "-") }
+        .map { (String($0[0]), String($0[1])) }.forEach { m1, m2 in
+            map[m1, default: []].insert(m2)
+            map[m2, default: []].insert(m1)
+        }
+    return map
+}
+
+struct Triple : Hashable, CustomStringConvertible {
+    let (m1, m2, m3): (String, String, String)
+    var description: String { return "\(m1)-\(m2)-\(m3)" }
+    var hasT: Bool {
+        return m1.first == "t" || m2.first == "t" || m3.first == "t"
+    }
+    init (_ m1: String, _ m2: String, _ m3: String) {
+        let ms = [m1, m2, m3].sorted()
+        (self.m1, self.m2, self.m3) = (ms[0], ms[1], ms[2])
+    }
+}
+
+func checkTriples(_ network: Network) -> Set<Triple> {
+    var triples: Set<Triple> = []
+    for (m1, m1conns) in network {
+        for m2 in m1conns {
+            for m3 in network[m2]! {
+                if network[m3]!.contains(m1) {
+                    triples.insert(Triple(m1, m2, m3))
+                }
+            }
+        }
+    }
+    return triples
+}
+            
+let conns = try readInput(CommandLine.arguments[1])
+print(checkTriples(conns).filter { $0.hasT }.count)

day23/test.txt

@@ -0,0 +1,32 @@
+kh-tc
+qp-kh
+de-cg
+ka-co
+yn-aq
+qp-ub
+cg-tb
+vc-aq
+tb-ka
+wh-tc
+yn-cg
+kh-ub
+ta-co
+de-co
+tc-td
+tb-wq
+wh-td
+ta-ka
+td-qp
+aq-cg
+wq-ub
+ub-vc
+de-ta
+wq-aq
+wq-vc
+wh-yn
+ka-de
+kh-ta
+co-tc
+wh-qp
+tb-vc
+td-yn