Status: IN
Excel column numbering is bijective base-26 (digits 1–26, no zero), not standard base-26 — this is why `convert_to_title` needs `columnNumber -= 1` each iteration and why `title_to_number` uses `ord(c) - ord('A') + 1`.
Source: entries/2026/06/06/excel-sheet-column-number-solution.md