Status: IN
The repo demonstrates two distinct merge-by-key strategies: `merge-similar-items` uses `defaultdict(int)` when inputs are unsorted, while `merge-two-2d-arrays` uses a two-pointer merge when inputs are pre-sorted — the choice is driven by the sorted precondition.
Source: entries/2026/06/06/merge-two-2d-arrays-by-summing-values-solution.md