updated 146 solution

Author: rustykitty

0146-lru-cache-stl.cpp

@@ -0,0 +1,50 @@
+/*
+146. LRU Cache
+
+Submitted: December 21, 2024
+
+Runtime: 71 ms (beats 78.21%)
+Memory: 182.15 MB (beats 27.80%)
+*/
+
+class LRUCache {
+private:
+    const int capacity;
+    unordered_map<int, list<pair<int, int>>::iterator> map;
+    list<pair<int, int>> list;
+public:
+    LRUCache(int capacity) : capacity(capacity) {}
+    
+    int get(int key) {
+        if (map.count(key)) {
+            int val = (*map[key]).second;
+            list.erase(map[key]);
+            list.push_front({ key, val });
+            map[key] = list.begin();
+            return val;
+        }
+        return -1;
+    }
+
+    void put(int key, int value) {
+        if (map.count(key)) {
+            list.erase(map[key]);
+            list.push_front({ key, value });
+            map[key] = list.begin();
+        } else {
+            if (list.size() == capacity) {
+                map.erase(list.back().first);
+                list.pop_back();
+            }
+            list.push_front({ key, value });
+            map[key] = list.begin();
+        }
+    }
+};
+
+/**
+ * Your LRUCache object will be instantiated and called as such:
+ * LRUCache* obj = new LRUCache(capacity);
+ * int param_1 = obj->get(key);
+ * obj->put(key,value);
+ */

0146-lru-cache.cpp

@@ -5,6 +5,9 @@ Submitted: November 30, 2024
 
 Runtime: 67 ms (beats 85.54%)
 Memory: 173.16 MB (beats 55.15%)
+
+A solution for this problem using the std::list class rather than a custom 
+LinkedList class is contained within `0146-lru-cache-stl.cpp`.
 */
 
 class LinkedList {