2025 day 1

.envrc

@@ -1,22 +1,5 @@
 #!/bin/bash
 
-# Copy these to a .env.local file to override in local host
-
-# This is what DIESEL cli uses
-export DATABASE_URL="test_db.db"
-
-## APP variables
-# /etc/stormd/stormd.db
-export STORMD_DB_PATH="stormd_db_local.db"
-export STORMD_DB_ENC_KEY_FILE="stormd_db_enc.key"
-# /etc/nebula/config.yml
-export STORMD_NEBULA_CONFIG="nebula_config.yml"
-# Auth key for admin API
-export STORMD_NEXUS_ADMIN_AUTH_FILE="stormd_auth_key"
-export STORMD_DAEMON_HTTP_PORT=37391
-
-# ======
-
 watch_file .env.local
 dotenv_if_exists .env.local
 

2025/day_1.nix

@@ -0,0 +1,44 @@
+# nix eval -f ./day_1.nix -I 'input=(builtins.readFile ./puzzle_cache/day_1_1)' countZero
+{ input ? (builtins.readFile ./puzzle_cache/day_1_0) }:
+let
+  utils = import ./utils.nix;
+  inherit (utils) toIntBase10 mod;
+
+  # Split into non-empty lines
+  lines = builtins.filter (s: builtins.isString s && s != "") (builtins.split "\n" input);
+
+  # Parse a line like "L68" or "R14"
+  parseLine = line: {
+    dir = builtins.substring 0 1 line;
+    dist = toIntBase10 (builtins.substring 1 (builtins.stringLength line - 1) line);
+  };
+
+  rotations = map parseLine lines;
+
+  # Fold over the list to simulate the dial
+  step =
+    state: rot:
+    let
+      position =
+        if rot.dir == "L" then
+          mod (state.position - rot.dist) 100
+        else if rot.dir == "R" then
+          mod (state.position + rot.dist) 100
+        else
+          builtins.trace "Invalid direction: ${rot.dir}" state.position;
+      countZero = state.countZero + (if position == 0 then 1 else 0);
+    in
+    {
+      inherit position countZero;
+    };
+
+  initialState = {
+    position = 50;
+    countZero = 0;
+  };
+
+  finalState = builtins.foldl' step initialState rotations;
+in
+{
+  inherit (finalState) position countZero;
+}

2025/puzzle_cache/day_1_0

@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82

2025/utils.nix

@@ -0,0 +1,4 @@
+{
+  toIntBase10 = str: builtins.fromJSON "${str}";
+  mod = a: b: a - b * (builtins.floor (a / b));
+}

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nix-filter": {
       "locked": {
-        "lastModified": 1731533336,
-        "narHash": "sha256-oRam5PS1vcrr5UPgALW0eo1m/5/pls27Z/pabHNy2Ms=",
+        "lastModified": 1757882181,
+        "narHash": "sha256-+cCxYIh2UNalTz364p+QYmWHs0P+6wDhiWR4jDIKQIU=",
         "owner": "numtide",
         "repo": "nix-filter",
-        "rev": "f7653272fd234696ae94229839a99b73c9ab7de0",
+        "rev": "59c44d1909c72441144b93cf0f054be7fe764de5",
         "type": "github"
       },
       "original": {
@@ -17,11 +17,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1733581040,
-        "narHash": "sha256-Qn3nPMSopRQJgmvHzVqPcE3I03zJyl8cSbgnnltfFDY=",
+        "lastModified": 1764950072,
+        "narHash": "sha256-BmPWzogsG2GsXZtlT+MTcAWeDK5hkbGRZTeZNW42fwA=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "22c3f2cf41a0e70184334a958e6b124fb0ce3e01",
+        "rev": "f61125a668a320878494449750330ca58b78c557",
         "type": "github"
       },
       "original": {
@@ -45,11 +45,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1733625333,
-        "narHash": "sha256-tIML2axjm4AnlKP29upVJxzBpj4Cy4ak+PKonqQtXmc=",
+        "lastModified": 1765161692,
+        "narHash": "sha256-XdY9AFzmgRPYIhP4N+WiCHMNxPoifP5/Ld+orMYBD8c=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "430c8b054e45ea44fd2c9521a378306ada507a6c",
+        "rev": "7ed7e8c74be95906275805db68201e74e9904f07",
         "type": "github"
       },
       "original": {