From c2c5fe923e8f161fdad4ad62e731b370872983a5 Mon Sep 17 00:00:00 2001
From: Elijah Voigt <elijah.caine.mv@gmail.com>
Date: Sun, 1 Mar 2026 19:47:32 -0800
Subject: [PATCH] markov chain exercise skeleton

---
 .../markov/weather-chain/.rust-version         |  1 +
 edu/exercises/markov/weather-chain/Cargo.lock  | 16 ++++++++++++++++
 edu/exercises/markov/weather-chain/Cargo.toml  |  7 +++++++
 edu/exercises/markov/weather-chain/src/main.rs | 18 ++++++++++++++++++
 4 files changed, 42 insertions(+)
 create mode 100644 edu/exercises/markov/weather-chain/.rust-version
 create mode 100644 edu/exercises/markov/weather-chain/Cargo.lock
 create mode 100644 edu/exercises/markov/weather-chain/Cargo.toml
 create mode 100644 edu/exercises/markov/weather-chain/src/main.rs

diff --git a/edu/exercises/markov/weather-chain/.rust-version b/edu/exercises/markov/weather-chain/.rust-version
new file mode 100644
index 0000000..bf867e0
--- /dev/null
+++ b/edu/exercises/markov/weather-chain/.rust-version
@@ -0,0 +1 @@
+nightly
diff --git a/edu/exercises/markov/weather-chain/Cargo.lock b/edu/exercises/markov/weather-chain/Cargo.lock
new file mode 100644
index 0000000..3ad6c0e
--- /dev/null
+++ b/edu/exercises/markov/weather-chain/Cargo.lock
@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "random"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d62d9cce151a97168445d78542558d3bddf6cf99f283c475f2eaf5cc14c364a"
+
+[[package]]
+name = "weather-chain"
+version = "0.1.0"
+dependencies = [
+ "random",
+]
diff --git a/edu/exercises/markov/weather-chain/Cargo.toml b/edu/exercises/markov/weather-chain/Cargo.toml
new file mode 100644
index 0000000..4d50e59
--- /dev/null
+++ b/edu/exercises/markov/weather-chain/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "weather-chain"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+rand = "0.10.0"
diff --git a/edu/exercises/markov/weather-chain/src/main.rs b/edu/exercises/markov/weather-chain/src/main.rs
new file mode 100644
index 0000000..7a22ef3
--- /dev/null
+++ b/edu/exercises/markov/weather-chain/src/main.rs
@@ -0,0 +1,18 @@
+use rand::Rng;
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+enum Weather { Sunny, Rainy }
+
+struct WeatherChain {
+    /// transition[current][next] = probability
+    transition: [[f64; 2]; 2],
+}
+
+impl WeatherChain {
+    fn step(&self, current: Weather, rng: &mut impl Rng) -> Weather { todo!() }
+    fn simulate(&self, start: Weather, steps: usize, rng: &mut impl Rng) -> Vec<Weather> { todo!() }
+}
+
+fn main() {
+    todo!()
+}