[1] Initial linked list implementation

anikinvd/docs/data/1-st-exercise/phonebook.py

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+
+def llist_insert(head, name, phone):
+    current = head
+    while current is not None:
+        if current['name'] == name:
+            current['phone'] = phone
+            return head
+        current = current['next']
+
+    new_node = {'name': name, 'phone': phone, 'next': None}
+
+    if head is None:
+        return new_node
+
+    current = head
+    while current['next'] is not None:
+        current = current['next']
+    current['next'] = new_node
+    return head
+
+
+def llist_find(head, name):
+    current = head
+    while current is not None:
+        if current['name'] == name:
+            return current['phone']
+        current = current['next']
+    return None
+
+
+def llist_delete(head, name):
+    if head is None:
+        return None
+
+    if head['name'] == name:
+        return head['next']
+
+    prev = head
+    current = head['next']
+    while current is not None:
+        if current['name'] == name:
+            prev['next'] = current['next']
+            return head
+        prev = current
+        current = current['next']
+    return head
+
+
+def llist_get_all(head):
+    entries = []
+    current = head
+    while current is not None:
+        entries.append((current['name'], current['phone']))
+        current = current['next']
+    entries.sort(key=lambda x: x[0])
+    return entries
+
+
+if __name__ == '__main__':
+    head = None
+    head = llist_insert(head, "Alice", "111-222")
+    head = llist_insert(head, "Bob", "333-444")
+    head = llist_insert(head, "Alice", "555-666")
+    print(llist_find(head, "Alice"))
+    print(llist_find(head, "Charlie"))
+    head = llist_delete(head, "Bob")
+    print(llist_get_all(head))