Ordered multiset

Write codeMedium25 min

Your task

Design an ordered multiset supporting ['add', x], ['remove', x] (remove one occurrence; no-op if absent), and ['rank', x] which returns the number of stored elements strictly less than x. Keep the structure sorted so each query is logarithmic in lookup. Given an op list, return the list of results for each 'rank'.

Examples

ordered_multiset(ops: list[list]) -> list[int]

Example 1

Inputordered_multiset([["add", 5], ["add", 3], ["add", 8], ["rank", 5], ["add", 5], ["rank", 5], ["rank", 9]])

Output[1, 1, 4]