[TASK] Finished Day 4

src/main.rs

@@ -5,6 +5,7 @@ mod util;
 mod day1;
 mod day2;
 mod day3;
+mod day4;
 
 fn main() {
 
@@ -18,6 +19,7 @@ fn main() {
             1 => day1::solve(),
             2 => day2::solve(),
             3 => day3::solve(),
+            4 => day4::solve(),
             _ => println!("This day is not yet implemented")
         }
     } else {
@@ -25,6 +27,7 @@ fn main() {
         day1::solve();
         day2::solve();
         day3::solve();
+        day4::solve();
     }
 
     println!("Execution took {} μs", now.elapsed().as_micros());