Implement string-based rounding without floats

Coding

You are not allowed to parse the input into a built-in floating type (to avoid overflow and precision issues). Work directly on strings.

1) Implement round(s) from scratch

Given a string s representing a decimal number, return a string representing the value rounded to the nearest integer.

• s may include an optional sign ( + / - ) and an optional decimal point.
• Examples of tricky inputs you must handle:
  • "-.2" (equivalent to -0.2 )
  • "2." (equivalent to 2.0 )
  • Very long integer parts that would overflow float()

Clarify and implement a deterministic tie-breaking rule (e.g., exactly .5 cases).

2) Round a numeric string s to a given precision p

Given two strings:

• s : a decimal number as a string
• p : a positive decimal precision as a string

Return s rounded to the nearest multiple of p (as a string).

Examples:

• s = "12567" , p = "100" → return "12600"
• s = "1234.678" , p = "0.1" → return "1234.7"

Assume p is a power of 10 (e.g., 1000, 0.01, 0.1). Specify how you format the output (e.g., whether to keep trailing zeros).