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LRU Cache for Fast Retrieval
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LRU Cache for Fast Retrieval

MediumPython

Problem

At Acme Analytics, repeated lookups for the same records are slowing down application performance. Implement an LRU (Least Recently Used) cache to optimize repeated data retrieval by keeping only the most recently accessed items in memory.

Design a class LRUCache that supports these operations in O(1) average time:

  1. get(key) — return the value for key if it exists, otherwise return -1.
  2. put(key, value) — insert or update the key-value pair. If the cache exceeds its capacity, evict the least recently used key.

Formal Specification

  • Input: A positive integer capacity, followed by a sequence of operations: get(key) and put(key, value).
  • Output: For each get(key), return the stored value or -1 if the key is not present.

Constraints

  • 1 <= capacity <= 10^5
  • 0 <= key, value <= 10^9
  • 1 <= operations.length <= 2 * 10^5
  • Each operation is either ["get", key] or ["put", key, value]
  • All get and put operations should run in O(1) average time

Function Signature

def run_lru_cache(capacity, operations):
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