[08_revisit_everything] fully automate the button

src/bin/main.rs

@@ -9,8 +9,10 @@ fn main() -> ExitCode {
         eprintln!("Usage: main NAME");
         return ExitCode::FAILURE;
     }
+    let mut name = args[1].clone();
 
-    let name = args[1].clone();
+    loop {
+        println!("\nAttempting to solve for \"{}\"", &name);
 
         print!("Solving challenge 01_welcome... ");
         let (n, x) = lib::challenges::c1_welcome::solve();
@@ -40,8 +42,21 @@ fn main() -> ExitCode {
         let (n, x) = lib::challenges::c7_weird_assembly_machine::solve(n, x);
         submit_or_fail(&name, n, x.clone());
 
-    println!("n = {n}");
+        print!("Solving challenge 08_revisit_everything... ");
-    println!("x = {x}");
+        let (n, x) = match lib::challenges::c8_revisit_everything::solve(n, x) {
+            Ok(res) => res,
+            Err(w) => {
+                println!("Failed. (w = {})", w);
+                name.insert_str(0, " ");
+                continue;
+            }
+        };
+        submit_or_fail(&name, n, x.clone());
+
+        println!("n = {}", n);
+        println!("x = {}", x);
+        break;
+    }
 
     ExitCode::SUCCESS
 }

src/lib/challenges/c8_revisit_everything.rs

@@ -0,0 +1,25 @@
+use rug::ops::DivRounding;
+use rug::Integer;
+use std::str::FromStr;
+use std::sync::LazyLock;
+
+static PHI: LazyLock<Integer> = LazyLock::new(|| Integer::from_str("4556683258594822402855414380362620295231673046713752880933967889771646856051745784462468117575177892006513392693685616565666555545842363207724851343853529903674824524238732001458342230627654145983386115997227846421784693186847971068054052064").unwrap());
+static M: LazyLock<Integer> = LazyLock::new(|| Integer::from_str("4556683258594822402855414380362620295231673046713752880933967889771646856051745784462468117575177892006513392693685616569935833357648393898915677206732580748330214938398411668157941515847730087263301030154072458063812554524260405671629754999").unwrap());
+static E: LazyLock<Integer> = LazyLock::new(|| Integer::from(65537));
+static TRUTH: LazyLock<Integer> = LazyLock::new(|| Integer::from(42));
+const LIMIT: u128 = 100_000_000_000_000_000_000;
+
+pub fn solve(n: u64, x: Integer) -> Result<(u128, Integer), u32> {
+    let k = Integer::from(LIMIT - n as u128) * 100;
+    let e = E.clone().pow_mod(&k, &PHI).unwrap();
+    let w: u32 = x.clone().modulo(&TRUTH).try_into().unwrap();
+    if w != 30 {
+        return Err(w);
+    }
+
+    let mut y = x.clone().div_floor(&*TRUTH);
+    y = y.pow_mod(&e, &M).unwrap();
+
+    let x: Integer = y * 42 + w;
+    Ok((LIMIT, x))
+}

src/lib/challenges/mod.rs

@@ -5,3 +5,4 @@ pub mod c4_broken_proof_of_work;
 pub mod c5_what_the_bf;
 pub mod c6_automation_is_not_enough;
 pub mod c7_weird_assembly_machine;
+pub mod c8_revisit_everything;