From 4e8b57681344c060fb5849a9b48b2f00c268f2b2 Mon Sep 17 00:00:00 2001
From: delmorallopez <124817272+delmorallopez@users.noreply.github.com>
Date: Tue, 24 Feb 2026 15:19:12 +0000
Subject: [PATCH 1/4] lru cache

---
 Sprint-2/implement_lru_cache/lru_cache.py     | 82 +++++++++++++++++++
 .../implement_lru_cache/lru_cache_test.py     |  1 -
 2 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement_lru_cache/lru_cache.py b/Sprint-2/implement_lru_cache/lru_cache.py
index e69de29..fcad074 100644
--- a/Sprint-2/implement_lru_cache/lru_cache.py
+++ b/Sprint-2/implement_lru_cache/lru_cache.py
@@ -0,0 +1,82 @@
+class Node:
+    def __init__(self, key, value):
+        self.key = key
+        self.value = value
+        self.previous = None
+        self.next = None
+
+
+class LruCache:
+    def __init__(self, limit):
+        if limit <= 0:
+            raise ValueError("Limit must be positive")
+
+        self.limit = limit
+        self.cache = {}  # key -> node
+        self.head = None  # Most recently used
+        self.tail = None  # Least recently used
+
+    # ---------------------
+    # Internal helpers
+    # ---------------------
+
+    def _remove_node(self, node):
+        if node.previous:
+            node.previous.next = node.next
+        else:
+            self.head = node.next
+
+        if node.next:
+            node.next.previous = node.previous
+        else:
+            self.tail = node.previous
+
+        node.previous = None
+        node.next = None
+
+    def _add_to_head(self, node):
+        node.next = self.head
+        node.previous = None
+
+        if self.head:
+            self.head.previous = node
+        else:
+            self.tail = node
+
+        self.head = node
+
+    # ---------------------
+    # Public API
+    # ---------------------
+
+    def get(self, key):
+        node = self.cache.get(key)
+        if not node:
+            return None
+
+        # Move to head (recently used)
+        self._remove_node(node)
+        self._add_to_head(node)
+
+        return node.value
+
+    def set(self, key, value):
+        node = self.cache.get(key)
+
+        if node:
+            # Update value and move to head
+            node.value = value
+            self._remove_node(node)
+            self._add_to_head(node)
+            return
+
+        # If full, evict LRU (tail)
+        if len(self.cache) >= self.limit:
+            lru = self.tail
+            self._remove_node(lru)
+            del self.cache[lru.key]
+
+        # Insert new node
+        new_node = Node(key, value)
+        self._add_to_head(new_node)
+        self.cache[key] = new_node
diff --git a/Sprint-2/implement_lru_cache/lru_cache_test.py b/Sprint-2/implement_lru_cache/lru_cache_test.py
index d37df01..666852b 100644
--- a/Sprint-2/implement_lru_cache/lru_cache_test.py
+++ b/Sprint-2/implement_lru_cache/lru_cache_test.py
@@ -1,5 +1,4 @@
 import unittest
-
 from lru_cache import LruCache
 
 class LruCacheTest(unittest.TestCase):

From 80670ec6224f3ea62bd197408a936fc5ae41104c Mon Sep 17 00:00:00 2001
From: delmorallopez <124817272+delmorallopez@users.noreply.github.com>
Date: Tue, 3 Mar 2026 16:21:48 +0000
Subject: [PATCH 2/4] lru cache update

---
 Sprint-2/implement_lru_cache/lru_cache.py | 49 +++++++++--------------
 1 file changed, 18 insertions(+), 31 deletions(-)

diff --git a/Sprint-2/implement_lru_cache/lru_cache.py b/Sprint-2/implement_lru_cache/lru_cache.py
index fcad074..31cd44c 100644
--- a/Sprint-2/implement_lru_cache/lru_cache.py
+++ b/Sprint-2/implement_lru_cache/lru_cache.py
@@ -1,10 +1,4 @@
-class Node:
-    def __init__(self, key, value):
-        self.key = key
-        self.value = value
-        self.previous = None
-        self.next = None
-
+from collections import OrderedDict
 
 class LruCache:
     def __init__(self, limit):
@@ -12,6 +6,7 @@ def __init__(self, limit):
             raise ValueError("Limit must be positive")
 
         self.limit = limit
+<<<<<<< HEAD
         self.cache = {}  # key -> node
         self.head = None  # Most recently used
         self.tail = None  # Least recently used
@@ -48,35 +43,27 @@ def _add_to_head(self, node):
     # ---------------------
     # Public API
     # ---------------------
+=======
+        self.cache = OrderedDict()
+>>>>>>> fc65c37 (lru cache update)
 
     def get(self, key):
-        node = self.cache.get(key)
-        if not node:
+        if key not in self.cache:
             return None
 
-        # Move to head (recently used)
-        self._remove_node(node)
-        self._add_to_head(node)
-
-        return node.value
+        # Move key to the end (most recently used)
+        value = self.cache.pop(key)
+        self.cache[key] = value
+        return value
 
     def set(self, key, value):
-        node = self.cache.get(key)
-
-        if node:
-            # Update value and move to head
-            node.value = value
-            self._remove_node(node)
-            self._add_to_head(node)
-            return
+        if key in self.cache:
+            # Update existing and move to end
+            self.cache.pop(key)
 
-        # If full, evict LRU (tail)
-        if len(self.cache) >= self.limit:
-            lru = self.tail
-            self._remove_node(lru)
-            del self.cache[lru.key]
+        elif len(self.cache) >= self.limit:
+            # Remove least recently used (first item)
+            self.cache.popitem(last=False)
 
-        # Insert new node
-        new_node = Node(key, value)
-        self._add_to_head(new_node)
-        self.cache[key] = new_node
+        # Insert as most recently used
+        self.cache[key] = value
\ No newline at end of file

From 486700ec7a6e9f7e260165714d5f9d10731c1e90 Mon Sep 17 00:00:00 2001
From: delmorallopez <124817272+delmorallopez@users.noreply.github.com>
Date: Tue, 3 Mar 2026 16:24:03 +0000
Subject: [PATCH 3/4] LRU Cache update

---
 Sprint-2/implement_lru_cache/lru_cache.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Sprint-2/implement_lru_cache/lru_cache.py b/Sprint-2/implement_lru_cache/lru_cache.py
index 31cd44c..6de6501 100644
--- a/Sprint-2/implement_lru_cache/lru_cache.py
+++ b/Sprint-2/implement_lru_cache/lru_cache.py
@@ -50,7 +50,6 @@ def _add_to_head(self, node):
     def get(self, key):
         if key not in self.cache:
             return None
-
         # Move key to the end (most recently used)
         value = self.cache.pop(key)
         self.cache[key] = value

From 238028a0aab5a1ff0e60b29669f266dc8503d77e Mon Sep 17 00:00:00 2001
From: delmorallopez <124817272+delmorallopez@users.noreply.github.com>
Date: Wed, 4 Mar 2026 10:28:47 +0000
Subject: [PATCH 4/4] lru cache update

---
 Sprint-2/implement_lru_cache/lru_cache.py | 44 +----------------------
 1 file changed, 1 insertion(+), 43 deletions(-)

diff --git a/Sprint-2/implement_lru_cache/lru_cache.py b/Sprint-2/implement_lru_cache/lru_cache.py
index 6de6501..bc8b928 100644
--- a/Sprint-2/implement_lru_cache/lru_cache.py
+++ b/Sprint-2/implement_lru_cache/lru_cache.py
@@ -6,63 +6,21 @@ def __init__(self, limit):
             raise ValueError("Limit must be positive")
 
         self.limit = limit
-<<<<<<< HEAD
-        self.cache = {}  # key -> node
-        self.head = None  # Most recently used
-        self.tail = None  # Least recently used
-
-    # ---------------------
-    # Internal helpers
-    # ---------------------
-
-    def _remove_node(self, node):
-        if node.previous:
-            node.previous.next = node.next
-        else:
-            self.head = node.next
-
-        if node.next:
-            node.next.previous = node.previous
-        else:
-            self.tail = node.previous
-
-        node.previous = None
-        node.next = None
-
-    def _add_to_head(self, node):
-        node.next = self.head
-        node.previous = None
-
-        if self.head:
-            self.head.previous = node
-        else:
-            self.tail = node
-
-        self.head = node
-
-    # ---------------------
-    # Public API
-    # ---------------------
-=======
         self.cache = OrderedDict()
->>>>>>> fc65c37 (lru cache update)
 
     def get(self, key):
         if key not in self.cache:
             return None
-        # Move key to the end (most recently used)
+
         value = self.cache.pop(key)
         self.cache[key] = value
         return value
 
     def set(self, key, value):
         if key in self.cache:
-            # Update existing and move to end
             self.cache.pop(key)
 
         elif len(self.cache) >= self.limit:
-            # Remove least recently used (first item)
             self.cache.popitem(last=False)
 
-        # Insert as most recently used
         self.cache[key] = value
\ No newline at end of file