mvp and stretch, albeit a little late.

names/names.py

@@ -13,10 +13,32 @@
 duplicates = []  # Return the list of duplicates in this data structure
 
 # Replace the nested for loops below with your improvements
+'''
 for name_1 in names_1:
     for name_2 in names_2:
         if name_1 == name_2:
             duplicates.append(name_1)
+'''
+name_counts = {}
+
+
+def add_name(d, name):
+    if d.get(name):
+        d[name] += 1
+    else:
+        d[name] = 1
+
+
+for name in names_1:
+    add_name(name_counts, name)
+
+for name in names_2:
+    add_name(name_counts, name)
+
+for key, value in name_counts.items():
+    if value > 1:
+        duplicates.append(key)
+
 
 end_time = time.time()
 print (f"{len(duplicates)} duplicates:\n\n{', '.join(duplicates)}\n\n")

reverse/reverse.py

@@ -12,6 +12,7 @@ def get_next(self):
     def set_next(self, new_next):
         self.next_node = new_next
 
+
 class LinkedList:
     def __init__(self):
         self.head = None
@@ -39,4 +40,12 @@ def contains(self, value):
         return False
 
     def reverse_list(self, node, prev):
-        pass
+        if node is None:
+            return
+        if node.get_next() is None:
+            self.head = node
+            node.set_next(prev)
+            return
+        next_node = node.get_next()
+        node.set_next(prev)
+        self.reverse_list(next_node, node)

ring_buffer/ring_buffer.py

@@ -1,9 +1,15 @@
 class RingBuffer:
     def __init__(self, capacity):
-        pass
+        self.storage = []
+        self.pointer = 0
+        self.capacity = capacity
 
     def append(self, item):
-        pass
+        if len(self.storage) < self.capacity:
+            self.storage.append(item)
+        else:
+            self.storage[self.pointer % self.capacity] = item
+        self.pointer += 1
 
     def get(self):
-        pass
+        return self.storage