LRU Cache
Design and implement a data structure for Least Recently Used (LRU) cache. It should support get and put operations.
- get(key): Get the value (which will always be positive) of the key if the key exists in the cache, otherwise return -1.
- put(key, value): Set or insert the value if the key is not already present. When the cache reached its capacity, it should invalidate the least recently used item before inserting a new item.
The cache is initialized with a positive capacity.
Can you do both operations in O(1) time complexity?
Input & Output
Input
operations — the operations
Output
the return values of get operations
Example
Input
operations = [ LRUCache 2 put 1 1 put 2 2 get 1 put 3 3 get 2 put 4 4 get 1 get 3 get 4 ]
Output
[1, -1, -1, 3, 4]
Explanation
See input.