How do I approach Coding & Algorithms interview questions?

Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

What difficulty level is this interview question?

This is a easy difficulty Coding & Algorithms question, commonly asked during Technical Screen rounds at Pinterest.

What role is this question designed for?

This question is commonly asked for Machine Learning Engineer candidates at Pinterest during technical interviews.

Implement string-based rounding without floats | Pinterest Interview Question

Quick Overview

This question evaluates proficiency in string-based numeric processing, arbitrary-precision arithmetic concepts, precise rounding rules including deterministic tie-breaking, and handling of sign and decimal edge cases, and falls under the Coding & Algorithms domain.

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).

Quick Overview

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).

Implement string-based rounding without floats

Quick Overview

Coding

1) Implement `round(s)` from scratch

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

Comments (0)

Implement string-based rounding without floats

Quick Overview

Coding

1) Implement `round(s)` from scratch

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

Comments (0)

Implement string-based rounding without floats

Quick Overview