day 7, wren

d7-wren/main.wren

@@ -0,0 +1,83 @@
+import "aoc" for AoC
+
+class Entry {
+    construct dir(parent) {
+        _parent = parent
+        _files = {}
+    }
+    construct file(parent, size) {
+        _parent = parent
+        _size = size
+    }
+
+    size { _size }
+    files { _files }
+    parent { _parent }
+    type { _files == null ? "file" : "dir" }
+
+    total_size {
+        if(_size) {
+            return _size
+        } else {
+            return _files.map {|entry| entry.value.total_size}.reduce {|a, b| a+b}
+        }
+    }
+
+    toString {
+        if(_files) {
+            return "{" + _files.map {|entry| entry.key + ": " + entry.value.toString}.join(", ") + "}"
+        } else {
+            return _size.toString
+        }
+    }
+
+    iter_dirs(fn) {
+        if(_files) {
+            fn.call(this)
+            for(file in _files) {
+                file.value.iter_dirs(fn)
+            }
+        }
+    }
+}
+
+var lines = AoC.input.split("\n").where {|x| x != ""}
+
+var root = Entry.dir(null)
+
+var current = root
+for(line in lines) {
+    if(line.startsWith("$ cd")) {
+        var path = line.replace("$ cd ", "")
+        if(path == "/") {
+            current = root
+        } else if(path == "..") {
+            current = current.parent
+        } else {
+            current = current.files[path]
+        }
+    } else if(line == "$ ls") {
+        // ignore
+    } else if(line.startsWith("dir ")) {
+        var path = line.replace("dir ", "")
+        if(!current.files[path]) current.files[path] = Entry.dir(current)
+    } else {
+        var split = line.split(" ")
+        var size = Num.fromString(split[0])
+        var path = split[1]
+        if(!current.files[path]) current.files[path] = Entry.file(current, size)
+    }
+}
+
+var sum_p1 = 0
+var smallest_p2 = Num.infinity
+
+var to_free = 30000000 - (70000000 - root.total_size)
+root.iter_dirs {|dir|
+    var size = dir.total_size
+    if(size <= 100000) sum_p1 = sum_p1 + size
+    if(size >= to_free && size <= smallest_p2) smallest_p2 = size
+}
+
+System.print(sum_p1)
+System.print(smallest_p2)