adding Data Structures and Algorithms II C950

Data Structures and Algorithms II — C950/Task 2 - Python files + Screenshots/hash_table.py

@@ -0,0 +1,66 @@
+# Student ID: 012498637
+# Student Name: Zakaria Benmoulay
+# Course: C950 - Data Structures and Algorithms II
+
+
+class ChainingHashTable:
+
+    # We are going to assigns all buckets with an empty list.
+    def __init__(self, initial_capacity=40):
+        # Let's initialize the hash table with empty bucket list entries.
+        self.table = []
+        for i in range(initial_capacity):
+            self.table.append([])
+
+    # This func inserts a new item into the hash table.
+    def insert(self, key, item):
+        # Get the bucket list where this item will go.
+        bucket = hash(key) % len(self.table)
+        bucket_list = self.table[bucket]
+
+        # Let's check if the key already exists and update it if found.
+        for kv in bucket_list:
+            if kv[0] == key:
+                kv[1] = item
+                return True
+
+        # otherwise, we insert the item to the end of list.
+        key_value = [key, item]
+        bucket_list.append(key_value)
+        return True
+
+    # This func returns the item if found, or None if not found.
+    def lookup(self, key):
+        # Let's find the correct bucket for this key.
+        bucket = hash(key) % len(self.table)
+        bucket_list = self.table[bucket]
+
+        # Let's search through the bucket for the matching key.
+        for kv in bucket_list:
+            if kv[0] == key:
+                return kv[1]
+        return None
+
+    # This func removes an item with matching key from the hash table.
+    def remove(self, key):
+        # Let's find the bucket where this key should exist.
+        bucket = hash(key) % len(self.table)
+        bucket_list = self.table[bucket]
+
+        # Let's search for and remove the matching key-value pair.
+        for kv in bucket_list:
+            if kv[0] == key:
+                bucket_list.remove([kv[0], kv[1]])
+                return print('Package ', key, 'successfully deleted.')
+
+        # Let's return None if the key is not found.
+        return None
+
+    # This func returns a list of all (key, value) tuples stored in the hash table.
+    # Let's use this to iterate through all packages when needed.
+    def get_all(self):
+        result = []
+        for bucket_list in self.table:
+            for kv in bucket_list:
+                result.append((kv[0], kv[1]))
+        return result