Create hash_set_linked_list.py

arrays_and_strings/hash_set_linked_list.py

@@ -0,0 +1,58 @@
+class HashSet:
+
+    def __init__(self):
+        self.key_range = 131
+        self.bucket = [LL_Bucket() for _ in range(self.key_range)]
+
+    def _hash(self, key):
+        return key % self.key_range
+
+    def add(self, element: int) -> None:
+        bucket_index = self._hash(element)
+        self.bucket[bucket_index].insert(element)
+    
+    def remove(self, element: int) -> None:
+        bucket_index = self._hash(element)
+        self.bucket[bucket_index].delete(element)
+
+    def contains(self, element: int) -> bool:
+        bucket_index = self._hash(element)
+        return self.bucket[bucket_index].exists(element)
+        
+
+class Node:
+    def __init__(self, value=None, next=None):
+        self.value = value
+        self.next = next
+
+
+class LL_Bucket:
+    def __init__(self):
+        # add a pseud head
+        self.head = Node(0)
+
+    def insert(self, value):
+        if not self.exists(value):
+            self.head.next =  Node(value, self.head.next)
+        else:
+            print(f'node {value} already exists')
+        
+    def delete(self, value):
+        prev = self.head
+        current = self.head.next
+        while current is not None:
+            if current.value == value:
+                prev.next = current.next
+                return True
+            prev = current
+            current = current.next
+        return False
+    
+    def exists(self, value):
+        current = self.head.next
+        while current is not None:
+            if current.value == value:
+                return True
+            current = current.next
+        return False
+