12-Hour to 24-Hour — Solution & Editorial
The two edge cases carry the problem: 12AM → 00, 12PM → 12; otherwise add 12 for PM.
Complexity: O(1)
Watch out: 12AM is midnight (00), 12PM is noon (12) — both break the naive +12 rule.
The two edge cases carry the problem: 12AM → 00, 12PM → 12; otherwise add 12 for PM.
Complexity: O(1)
Watch out: 12AM is midnight (00), 12PM is noon (12) — both break the naive +12 rule.