.

2021/12.js

@@ -0,0 +1,42 @@
+// TODO: not very efficient because i was lazy
+
+function day12(input, part2) {
+    let cxns = input.split("\n").map((line) => line.split("-"))
+    let dict = {}
+
+    for (let cxn of cxns) {
+        dict[cxn[0]] = [...(dict[cxn[0]] || []), cxn[1]]
+        dict[cxn[1]] = [...(dict[cxn[1]] || []), cxn[0]]
+    }
+
+    let count = 0
+    let paths = [["start"]]
+
+    while (paths.length) {
+        let newPaths = []
+
+        for (let path of paths) {
+            for (let next of dict[path.last]) {
+                if (next == "start") {
+                    continue
+                }
+
+                let newPath = [...path, next]
+
+                if (newPath.count((e, i, a) => e == e.toLowerCase() && a.indexOf(e) != i) > part2) {
+                    continue
+                }
+
+                if (next == "end") {
+                    count++
+                } else {
+                    newPaths.push(newPath)
+                }
+            }
+        }
+
+        paths = newPaths
+    }
+
+    return count
+}