fix float formatting for 84

src/euler84/src/lib.rs

@@ -284,7 +284,7 @@ impl Statistics {
             .collect();
         result.sort_unstable_by(|(_, v1), (_, v2)| v2.partial_cmp(v1).unwrap());
         for (s, v) in result {
-            println!("{s:?}: {v}");
+            println!("{s:?}: {v:.2}");
         }
     }
 }