feat(rs): add hhcn

.gitignore

@@ -1,2 +1,4 @@
 .idea
 *.exe
+debug
+target

rs/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "claoj"
+version = "0.0.1"

rs/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "claoj"
+version = "0.0.1"
+edition = "2024"
+
+[[bin]]
+name = "hhcn"
+path = "hhcn.rs"

rs/hhcn.rs

@@ -0,0 +1,15 @@
+use std::io::{self, BufRead};
+
+fn main() {
+    let mut input = String::new();
+    io::stdin().lock().read_line(&mut input).unwrap();
+
+    let mut nums = input.split_whitespace().map(|x| x.parse::<f64>().unwrap());
+
+    let a = nums.next().unwrap();
+    let b = nums.next().unwrap();
+    let c = nums.next().unwrap();
+
+    let result = 4.0 * (a * b + b * c + c * a) / (a * b * c).sqrt();
+    println!("{}", result);
+}