remove dead code in 51

src/euler54/src/card.rs

@@ -85,22 +85,6 @@ impl Cards {
         self.value_hashmap.contains_key(value)
     }
 }
-
-trait Contains<T> {
-    fn contains_value(&self, x: &T) -> bool;
-}
-
-impl Contains<Value> for &CardsArray {
-    fn contains_value(&self, x: &Value) -> bool {
-        for card in self.iter() {
-            if card.value == *x {
-                return true;
-            }
-        }
-        false
-    }
-}
-
 pub trait CardTrait {
     fn to_value_hashmap(&self) -> HashMap<Value, usize>;
     fn to_suit_hashset(&self) -> HashSet<Suit>;
@@ -117,10 +101,7 @@ impl CardTrait for CardsArray {
     }
 
     fn to_value_hashmap(&self) -> HashMap<Value, usize> {
-        let mut hm = HashMap::new();
-        for value in self.to_value_hashset() {
-            hm.insert(value, 0);
-        }
+        let mut hm = HashMap::from_iter(self.to_value_hashset().iter().map(|v| (*v, 0)));
         for card in self {
             *hm.get_mut(&card.value).unwrap() += 1;
         }