Nested comment stripper: hints, no solution
Medium · Stack
A build tool for a small scripting language must strip comments before parsing. A comment starts at the two characters slash-star and ends at the matching star-slash. Unlike many languages, comments here can nest: every slash-star inside a comment opens another level, and the comment only ends when every level has been closed.
Read the source from left to right, two characters at a time: a marker is always two characters and is never reused, so slash-star-slash is an opening marker followed by a lone slash. A star-slash that appears outside any comment is ordinary text. A comment that is never closed runs to the end of the source.
Return the source with all comment text, markers included, removed. Everything else, including newlines, is kept as is.
Examples
- Input
- source = "int a; /* note */ int b;"
- Output
- "int a; int b;"
- Note
- Only the comment text goes; both spaces around it are kept.
- Input
- source = "x /* a /* b */ c */ y"
- Output
- "x y"
- Note
- The inner close only ends the inner comment, so the whole span is removed and only x and y remain.
Constraints
- 0 <= source.length <= 12000
- Source characters are printable ASCII and newlines
Hint 1: a nudge
While you are inside a comment, what does seeing another opening marker change about when you may stop skipping?
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