c3: init

Cargo.lock

@@ -16,6 +16,10 @@ dependencies = [
  "geometry",
 ]
 
+[[package]]
+name = "challenge-3"
+version = "0.1.0"
+
 [[package]]
 name = "geometry"
 version = "0.1.0"

Cargo.toml

@@ -8,4 +8,5 @@ members = [
     # Challenge
     "challenges/december-2024/c1",
     "challenges/december-2024/c2",
+    "challenges/december-2024/c3",
 ]

challenges/december-2024/c3/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "challenge-3"
+version = "0.1.0"
+edition = "2021"
+
+
+

challenges/december-2024/c3/src/main.rs

@@ -0,0 +1,48 @@
+use std::io::{self, Write};
+
+// Sudan function is quite simple, here's the basics:the basics:
+// When n = 0, `F(n, x, y) = x + y`
+// When y = 0, `F(n, x, y) = x`
+// Otherwise, `F(n, x, y) = F(n - 1, F(n, x, y - 1), F(n, x, y - 1) + y)`
+fn sudan(n: i64, x: i64, y: i64) -> i64 {
+    if n == 0 {
+        x + y
+    } else if y == 0 {
+        x
+    } else {
+        sudan(n - 1, sudan(n, x, y - 1), sudan(n, x, y - 1) + y)
+    }
+}
+
+fn get_input<T: std::str::FromStr>(prompt: &str) -> Result<T, String> {
+    print!("{}", prompt);
+    io::stdout().flush().expect("Failed to flush stdout");
+
+    let mut input = String::new();
+    io::stdin()
+        .read_line(&mut input)
+        .map_err(|_| "Failed to read line".to_string())?;
+
+    input
+        .trim()
+        .parse::<T>()
+        .map_err(|_| "Invalid input. Please enter a valid number.".to_string())
+}
+
+fn get_input_value<T: std::str::FromStr>(prompt: &str) -> T {
+    loop {
+        match get_input(prompt) {
+            Ok(value) => return value,
+            Err(e) => eprintln!("{}", e),
+        }
+    }
+}
+
+fn main() {
+    let n: i64 = get_input_value("Enter the value for n: ");
+    let x: i64 = get_input_value("Enter the value for x: ");
+    let y: i64 = get_input_value("Enter the value for y: ");
+
+    let result = sudan(n, x, y);
+    println!("The result of F({}, {}, {}) is: {}", n, x, y, result);
+}