added solution to repo

solution.md

@@ -0,0 +1,10 @@
+# Advent of code 2025
+```day01:A =>            1150  (   283us)
+day01:B =>            6738  (   100us)
+day02:A =>     31839939622  (  8230us)
+day02:B =>     41662374059  ( 64586us)
+day03:A =>           16812  (  1506us)
+day03:B => 166345822896410  (   322us)
+                            ----------
+                              75267us
+```

src/main.rs

@@ -1,9 +1,22 @@
+use std::fmt::format;
 use std::time::Instant;
 use day01::{part01a, part01b};
 use day02::{part02a, part02b};
 use day03::{part03a, part03b};
 
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::io::Result;
+
 fn main() {
+    let mut file = OpenOptions::new()
+        .write(true)      // Open the file for writing
+        .create(true)     // Create the file if it doesn't exist
+        .truncate(true)   // Clear the file if it already exists
+        .open("solution.md").expect("Cannot open or create file");
+
+    file.write_all(b"# Advent of code 2025\n```").expect("Cannot write to file");
+
     let exercises: Vec<(&str, fn () -> u64)> = vec![
         ("day01:A", part01a::solve),
         ("day01:B", part01b::solve),
@@ -16,9 +29,16 @@ fn main() {
     let start: Instant = Instant::now();
     exercises.iter().for_each(|(day, func)| {
         let day_start: Instant = Instant::now();
-        println!("{:7} => {:15}  ({:6}us)", day, func(), day_start.elapsed().as_micros());
+        let solution = format!("{:7} => {:15}  ({:6}us)\n", day, func(), day_start.elapsed().as_micros());
+        print!("{}", solution);
+        file.write(solution.as_bytes()).expect("Cannot write to file");
     });
 
-    println!("                            ----------");
+    let banner = "                            ----------\n";
-    println!("                            {:7}us", start.elapsed().as_micros());
+    let end_time = format!("                            {:7}us\n", start.elapsed().as_micros());
+    print!("{}", banner);
+    file.write(banner.as_bytes()).expect("Cannot write to file");
+    println!("{}", end_time);
+    file.write(end_time.as_bytes()).expect("Cannot write to file");
+    file.write(b"```").expect("Cannot write to file");
 }