From c1ffafab0fab37e079a8b1937e6d4074401f2c3e Mon Sep 17 00:00:00 2001
From: Rui Hu <8199515+logreg-n-coffee@users.noreply.github.com>
Date: Wed, 20 Dec 2023 00:05:49 -0700
Subject: [PATCH] Add Python solution to Q 52

---
 code/52-least-recently-used-cache.py | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 code/52-least-recently-used-cache.py

diff --git a/code/52-least-recently-used-cache.py b/code/52-least-recently-used-cache.py
new file mode 100644
index 0000000..a65d821
--- /dev/null
+++ b/code/52-least-recently-used-cache.py
@@ -0,0 +1,25 @@
+from collections import OrderedDict
+
+
+# O(1) time complexity: __init__, get, and put are O(1)
+# O(n) space complexity: size of the cache
+class LRUCache:
+    def __init__(self, capacity: int):
+        self.cache = OrderedDict()  # cache to store key-value pairs
+        self.capacity = capacity  # max capacity of cache
+
+    def get(self, key: int) -> int:
+        # if key is in the cache, move it to the end
+        if key in self.cache:
+            self.cache.move_to_end(key)
+            return self.cache[key]
+        return -1
+
+    def put(self, key: int, value: int) -> None:
+        # if key is in the cache, move it to the end
+        if key in self.cache:
+            self.cache.move_to_end(key)
+        self.cache[key] = value
+        # if the cache is full, pop the first item (least recently used)
+        if len(self.cache) > self.capacity:
+            self.cache.popitem(last=False)