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Implement Core Data Structures
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Implement Core Data Structures

EasyPython

Problem

Quantori services may need a bounded in-memory cache for recently accessed event-processing results. Implement a Least Recently Used (LRU) cache that evicts the least recently accessed item when its capacity is exceeded.

Your function receives a positive capacity and a sequence of operations. Each operation is either get(key) or put(key, value). A get returns the stored value, or -1 if the key is absent. A successful get marks the key as most recently used. A put inserts or updates a key and marks it as most recently used. If insertion exceeds the capacity, remove the least recently used key. Return the results of all get operations in order.

Formal Specification

Implement lru_cache_operations(capacity, operations).

  • capacity is an integer.
  • operations is a list of tuples. Each tuple is either ("get", key) or ("put", key, value).
  • key and value are integers.
  • Return a list of integers containing one result for each get operation.

Constraints

  • 1 <= capacity <= 10^5
  • 0 <= operations.length <= 2 * 10^5
  • Keys and values are integers in the range [-10^9, 10^9]
  • Each operation is valid and has either two or three elements

Function Signature

def lru_cache_operations(capacity, operations):
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