Update lru_cache.cpp

Author: avidLearnerInProgress

lru_cache.cpp

@@ -13,15 +13,15 @@ class LRUCache {
             mp[key].second = keys.begin(); //update map
             return mp[key].first;
         }
-        else return -1;
+        return -1;
     }
 
     void put(int key, int value) {
         if(mp.find(key) != mp.end()) { //key already exists in the map
             //same operations as that of get operation
             keys.erase(mp[key].second);
             keys.push_front(key);
-            mp[key].second = keys.begin();
+            mp[key] = {value, keys.begin()};
         }
         else {
             if(keys.size() == capacity) {