Implement string compression and decompression
Company: NVIDIA
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Technical Screen
Implement two functions for a simple string compression format.
- `compress(s)`: convert a string into groups of consecutive equal characters written as `<char><count>`.
- `decompress(t)`: reconstruct the original string from that encoded form.
Example:
- `compress("aaabbccccd")` -> `"a3b2c4d1"`
- `decompress("a3b2c4d1")` -> `"aaabbccccd"`
Assume the input contains only English letters. Counts may have multiple digits, such as `a12`. Explain how you would handle invalid encoded input.
Quick Answer: This question evaluates proficiency in string manipulation, run-length encoding concepts, parsing numeric counts, and validation of encoded formats, including handling invalid inputs. It is in the Coding & Algorithms domain and is primarily a practical implementation task that also probes conceptual understanding of parsing, edge-case reasoning, and efficiency trade-offs.