diff --git a/2022/d9/.gitignore b/2022/d9/.gitignore
new file mode 100644
index 0000000..bd32e74
--- /dev/null
+++ b/2022/d9/.gitignore
@@ -0,0 +1,2 @@
+.direnv
+target
diff --git a/2022/d9/Cargo.lock b/2022/d9/Cargo.lock
new file mode 100644
index 0000000..0235225
--- /dev/null
+++ b/2022/d9/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "d9"
+version = "0.1.0"
diff --git a/2022/d9/Cargo.toml b/2022/d9/Cargo.toml
new file mode 100644
index 0000000..20ff77d
--- /dev/null
+++ b/2022/d9/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "d9"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/2022/d9/aoc/Cargo.lock b/2022/d9/aoc/Cargo.lock
new file mode 100644
index 0000000..a5b53ef
--- /dev/null
+++ b/2022/d9/aoc/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc"
+version = "0.1.0"
diff --git a/2022/d9/aoc/Cargo.toml b/2022/d9/aoc/Cargo.toml
new file mode 100644
index 0000000..706d2e1
--- /dev/null
+++ b/2022/d9/aoc/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "aoc"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/2022/d9/aoc/src/main.rs b/2022/d9/aoc/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/2022/d9/aoc/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/2022/d9/flake.lock b/2022/d9/flake.lock
index a62a638..5724db4 100644
--- a/2022/d9/flake.lock
+++ b/2022/d9/flake.lock
@@ -15,6 +15,21 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "locked": {
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1670064435,
@@ -31,10 +46,46 @@
         "type": "github"
       }
     },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1665296151,
+        "narHash": "sha256-uOB0oxqxN9K7XGF1hcnY+PQnlQJ+3bP2vCn/+Ru/bbc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "14ccaaedd95a488dd7ae142757884d8e125b3363",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1670552927,
+        "narHash": "sha256-lCE51eAGrAFS4k9W5aDGFpVtOAwQQ/rFMN80PCDh0vo=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "a0fdafd18c9cf599fde17fbaf07dbb20fa57eecb",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
       }
     }
   },
diff --git a/2022/d9/flake.nix b/2022/d9/flake.nix
index a0f5e43..dc3876a 100644
--- a/2022/d9/flake.nix
+++ b/2022/d9/flake.nix
@@ -3,26 +3,40 @@
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay.url = "github:oxalica/rust-overlay";
   };
-  outputs = { nixpkgs, flake-utils, ... } @ inputs:
+  outputs = { nixpkgs, flake-utils, rust-overlay, ... } @ inputs:
     flake-utils.lib.eachSystem flake-utils.lib.defaultSystems (sys:
       let
-        overlays = [ ];
+        overlays = [ rust-overlay.overlays.default ];
         pkgs = import nixpkgs { system = sys; overlays = overlays; };
         shellHookAfter = ''
           echo "The input files should be placed under ./data/{submission,example}.txt"
           echo "This problem shares one input between two parts"
         '';
         py_pkgs = [ pkgs.python310 ];
+        rs_pkgs = [
+          pkgs.openssl
+          pkgs.pkg-config
+
+          # Add rust-src, which rust-analyzer seems to rely upon
+          (pkgs.rust-bin.selectLatestNightlyWith
+            (
+              toolchain:
+              toolchain.default.override {
+                extensions = [ "rust-src" ];
+              }
+            ))
+        ];
       in
       {
         # Jack of all trades
         devShell = pkgs.mkShell
           {
-            nativeBuildInputs = py_pkgs ++ ocaml_pkgs;
+            buildInputs = py_pkgs ++ rs_pkgs;
             shellHook = ''
-              echo "> Default runtime. This contains both ocaml and python3 env"
-              echo "Run ./run-py.sh for Python's output and ./run-oml.sh for OCaml's output"
+              echo "> Default runtime. This contains both rust and python3 env"
+              echo "Run ./run-py.sh for Python's output and ./run-rs.sh for Rust's output"
             '' + shellHookAfter;
           };
         devShells = {
@@ -38,6 +52,13 @@
           # nix develop ./#fennel
 
           # nix develop ./#python
+          rust = pkgs.mkShell {
+            nativeBuildInputs = rs_pkgs;
+            shellHook = ''
+              echo "> Rust runtime"
+              echo "Run ./run-rs.sh to see output of the solution"
+            '' + shellHookAfter;
+          };
           python = pkgs.mkShell {
             nativeBuildInputs = py_pkgs;
             shellHook = ''
diff --git a/2022/d9/src/d9.py b/2022/d9/src/d9.py
index 4d33bc0..c6de296 100644
--- a/2022/d9/src/d9.py
+++ b/2022/d9/src/d9.py
@@ -1,18 +1,18 @@
 #!/usr/bin/env python3
 import sys
-from typing import Iterable, Generator
-from functools import reduce
-from itertools import product
+from typing import Iterable
 
 def add_nd(lhs: Iterable[int], rhs: Iterable[int]):
+    # Add two generic n-d vector together
     return tuple(l + r for l, r in zip(lhs, rhs))
 def negate_nd(vec: Iterable[int]):
+    # Negates a generic n-d vector
     return tuple(-e for e in vec)
-def norm_1k_nd(vec: Iterable[int]):
-    return sum(abs(e) for e in vec)
 def norm_infk_nd(vec: Iterable[int]):
+    # Mathematical concept where I get the length of the longest vector component
     return max(abs(e) for e in vec)
-
+def sign(e: int):
+    return 0 if e == 0 else (1 if e > 0 else -1)
 
 def dir_to_offset(dir: str):
     match dir:
@@ -26,8 +26,6 @@ def dir_to_offset(dir: str):
             return (1, 0)
         case d:
             raise RuntimeError(f"Unknown direction {d}")
-def sign(e: int):
-    return 0 if e == 0 else (1 if e > 0 else -1)
 
 def move_knot(knot: list[tuple[int, int]], offset: Iterable[int]):
     knot.append(add_nd(knot[-1], offset))
@@ -35,50 +33,44 @@ def move_knot(knot: list[tuple[int, int]], offset: Iterable[int]):
 
 def part1(commands: list[tuple[str, int]]):
     tail_locs: list[tuple[int, int]] = [(0,0)] # keeps track of where tail moved
+    # NOTE: I don't need to keep track of head's history here. This is only
+    # for ease of debugging
     head_locs : list[tuple[int, int]] = [(0,0)] # keeps track of where head moved
     for dir, rep in commands:
         for _ in range(rep):
             move_knot(head_locs, dir_to_offset(dir))
             offset = add_nd(head_locs[-1], negate_nd(tail_locs[-1]))
             # print(f"{offset=}")
-            match norm_1k_nd(offset), norm_infk_nd(offset):
-                case (0, _) | (1, _) | (2, 1):
-                    pass # don't need to catchup
-                case (_, _):
-                    # negate & normalize in inf_k
-                    move_knot(tail_locs, (sign(e) for e in offset))
-                case e:
-                    raise RuntimeError(f"Unknown case {e}\n{tail_locs=}\n{head_locs=}")
+            if norm_infk_nd(offset) <= 1:
+                continue # no need to catch up
+            move_knot(tail_locs, (sign(e) for e in offset))
     # print(f"{tail_locs=}")
     # print(f"{head_locs=}")
-
     return len(set(tail_locs))
 
 def part2(commands: list[tuple[str, int]]):
     KNOTS = 10
+    # NOTE: I don't need to keep track of any history but tail's. This is only
+    # for ease of debugging
     locs = [[(0,0)] for _ in range(KNOTS)] # 10 knots :)
     for dir, rep in commands:
         for _ in range(rep):
             move_knot(locs[0], dir_to_offset(dir)) # move head
             for i in range(1, KNOTS):
                 offset = add_nd(locs[i-1][-1], negate_nd(locs[i][-1]))
-                match norm_1k_nd(offset), norm_infk_nd(offset):
-                    case (0, _) | (1, _) | (2, 1):
-                        pass # don't need to catchup
-                    case (_, _):
-                        # negate & normalize in inf_k
-                        move_knot(locs[i], (sign(e) for e in offset))
-                    case e:
-                        raise RuntimeError(f"Unknown case {e}\n{locs[i]=}\n{locs[i-1]=}")
+                if norm_infk_nd(offset) <= 1:
+                    continue # no need to catch up
+                move_knot(locs[i], (sign(e) for e in offset))
     return len(set(locs[-1]))
 
 
 
 def main(lines: Iterable[str]):
     splited = (line.strip().split() for line in lines)
-    striped_lines = [(comp[0], int(comp[1])) for comp in splited if len(comp) > 0]
-    # print(striped_lines)
-    commands = [(comp[0], int(comp[1])) for comp in striped_lines]
+    # -> ["   D 4    ",...] -> [["D", "4"], ...]
+    ## Filters out any line that has empty newline and turn repitions into int
+    commands = [(comp[0], int(comp[1])) for comp in splited if len(comp) > 0]
+    # -> [[], ["D", "4"], ...] -> [["D", 4]]
     print("part1", part1(commands))
     print("part2", part2(commands))
     pass
@@ -86,3 +78,4 @@ def main(lines: Iterable[str]):
 if __name__=="__main__":
     with open(sys.argv[1], "r") as f:
         main(f)
+
diff --git a/2022/d9/src/main.rs b/2022/d9/src/main.rs
new file mode 100644
index 0000000..dfafdbc
--- /dev/null
+++ b/2022/d9/src/main.rs
@@ -0,0 +1,6 @@
+fn main() {
+    // let test = include_str!("../data/example.txt");
+    let sub = inlcude_str!("../data/submission.txt");
+    let commands = sub.lines()
+        .map(|line| line.split(" "))
+}