Problem · Design
File-Content LRU Cache
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AmazonFULLTIMEONSITE INTERVIEW
See Amazon hiring insightsAmazonFULLTIMEONSITE INTERVIEWProblem statement
Simulate a least-recently-used cache that stores file contents. The cache holds at most capacity files.
Each operation is either PUT|path|content or GET|path. A PUT inserts or replaces the complete content. A successful GET returns the content and makes that path most recently used; a missing path returns the empty string. When a new path exceeds capacity, evict the least recently used path.
Return all GET results in operation order.
Function
runFileCache(capacity: int, operations: String[]) → String[]Examples
Example 1
capacity = 2operations = ["PUT|/a|alpha","PUT|/b|beta","GET|/a","PUT|/c|gamma","GET|/b","GET|/c"]return = ["alpha","","gamma"]Reading /a refreshes it, so /b is evicted by the insertion of /c.
Example 2
capacity = 1operations = ["PUT|/x|old","PUT|/x|new","GET|/x"]return = ["new"]Replacing one path updates its content without increasing cache size.
Constraints
0 <= capacity <= 500001 <= operations.length <= 100000- Paths and contents are non-empty printable strings and do not contain
|. - The empty string is reserved for a cache miss.