Multiset: improve duplicate-key performance and use size t for sizes
Multiset: improve duplicate-key performance and use size t for sizes: a task in LegoFlow-SWE (Harbor dataset). With the duplicate‑allocation problem fixed, the same workload (insert 1 000 000 sequential integers, then check multiset contains for each) should run in approximately 0.50 seconds —…
The task
With the duplicate‑allocation problem fixed, the same workload (insert 1 000 000 sequential integers, then check `multiset_contains` for each) should run in approximately 0.50 seconds — about a 30 % improvement over the current 0.68 seconds.
Part of Lego-X/LegoFlow-SWE.