Lock Ordering to Prevent Deadlock

Given requests, a list of integer lock-ID lists (one per worker), return each worker's acquisition order. Deduplicate that worker's IDs and sort them ascending; retain the outer worker order. Every worker must use the same total order to eliminate circular wait. Empty requests and negative lock IDs are valid. This exercise builds a safe acquisition plan; it does not execute threads or simulate waiting. Locks are released in reverse order after the critical section. Examples (JSON; null means Python None): Input: {"requests": [[2, 1], [1, 2]]} Output: [[1, 2], [1, 2]] Input: {"requests": [[3, 3, 1], []]} Output: [[1, 3], []]

def ordered_locks(requests: list[list[int]]) -> list[list[int]]:
    """Return a common ascending, duplicate-free lock plan for every worker."""
    pass