Input Parsing - rFronteddu/general_wiki GitHub Wiki

• Tokenization (Split & Parse)
• Line-By-Line Parsing
• Unkn Line Count
• Filtering Garbage
• Extracting Numbers from text
• Handling Quoted Strings
• Normalize Case + White Space
• Parsing Dates and Time
• Parsing Nested Data
• Robust Handling

Drills:

How to Practice This Efficiently

• Daily (15–25 min):
  • Pick 2 drills
  • Write parser in your interview language
  • Add 3 edge cases
  • Time yourself (10 min limit)
  • Refactor to cleaner version

Clean Number List

Input:

" 1,  2, abc, -3, 4x, 5 "

Return [1, 2, -3, 5]

Command Parser

Input:

ADD 12
SUB 3
MUL   7
DIV two
ADD 5

Goal: Ignore invalid commands, compute final value

CSV Reader

Input:

Bob,25,"New York, USA"
Alice,  30,  "LA"

Goal: Parse into structured records

Log Scanner

Input:

[INFO] 2026-01-21 User=123 Action=Login
[ERROR] 2026-01-21 User=abc Action=Logout

Goal: Extract only valid numeric user IDs

Bracketed List Parser

Input

"[1,[2,3],[],[4,[5]]]"

Goal: Build nested lists

Streaming Integers

Input:

1 2 3
4 five 6
7 8 nine

Goal: Sum only valid integers