🔵 Extract magic number to constant

Author: isaac1024

exercises/tiered_pricing/solutions/isaac1024_baby-steps/src/tiered_pricing.rs

@@ -3,10 +3,11 @@ fn get_total_subscription_price(number_of_subscriptions: u32) -> u32 {
     const SECOND_UNIT_PRICE: u32 = 239;
     const THIRD_UNIT_PRICE: u32 = 219;
     const FOURTH_UNIT_PRICE: u32 = 199;
+    const FIFTH_UNIT_PRICE: u32 = 149;
 
     match number_of_subscriptions {
-        51 => 149 * number_of_subscriptions,
-        52 => 149 * number_of_subscriptions,
+        51 => FIFTH_UNIT_PRICE * number_of_subscriptions,
+        52 => FIFTH_UNIT_PRICE * number_of_subscriptions,
         1|2 => FIRST_UNIT_PRICE * number_of_subscriptions,
         3..=10 => SECOND_UNIT_PRICE * number_of_subscriptions,
         11..=25 => THIRD_UNIT_PRICE * number_of_subscriptions,