How do I practice coding and algorithm questions?

Use PracHub's coding console to write, test, and debug your solutions in Python or JavaScript. View hints, test against sample inputs, and compare with official solutions.

What difficulty level is this coding question?

This is a medium difficulty Coding & Algorithms question, commonly asked during Onsite rounds at Microsoft.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Microsoft during technical interviews.

Validate a JSON-like string | Microsoft Coding Question

Q: Validate a JSON-like string

This question evaluates parsing and string-processing skills, focusing on structural validation of JSON-like text including matching and nesting of brackets and correct handling of quoted strings with escape sequences.

Validate a JSON-like string

Company: Microsoft

Role: Software Engineer

Category: Coding & Algorithms

Difficulty: medium

Interview Round: Onsite

## Problem You are given a string `s` that is intended to be a JSON text. Implement a function `isValidJsonStructure(s) -> bool` that checks **structural validity** of the JSON with the following simplified rules: ### Rules to validate 1. After ignoring leading/trailing whitespace, the text must start and end with matching outer brackets: - either `{ ... }` or `[ ... ]`. 2. Brackets must be **properly nested and balanced**: - curly braces `{}` - square brackets `[]` 3. JSON strings are delimited by **double quotes** `"..."`. - While inside a string, any bracket characters (`{ } [ ]`) must be ignored for nesting purposes. - A quote preceded by an **odd** number of backslashes is escaped (e.g., `\"` closes? no; `\"` contains an escaped quote). In other words, `"` does **not** end a string. 4. You do **not** need to validate JSON key/value grammar (colons, commas, numbers, `true/false/null`, etc.). Only validate the above structural properties. ### Input/Output - **Input:** string `s` - **Output:** `true` if structurally valid per the rules; otherwise `false`. ### Constraints - `1 <= len(s) <= 1e5` ### Examples - `"{\"a\":[1,2,3]}"` → `true` - `"{[}]"` → `false` (bad nesting) - `"{\"x\":\"[}\"}"` → `true` (brackets inside a string are ignored) - `"{\"a\":\"unterminated}"` → `false` (unclosed string)

Quick Answer: This question evaluates parsing and string-processing skills, focusing on structural validation of JSON-like text including matching and nesting of brackets and correct handling of quoted strings with escape sequences.

Return whether a JSON-like string has matching outer brackets and balanced nested brackets while ignoring bracket characters inside strings.

Constraints

Only structural bracket validity is checked.
Quotes preceded by an odd number of backslashes are escaped.
JSON key/value grammar is not validated.

Examples

Input: ('{"a":[1,2,3]}',)

Expected Output: True

Explanation: Balanced brackets outside strings are valid.

Input: ('{[}]',)

Expected Output: False

Explanation: Bad nesting is invalid.

Input: ('{"x":"[not a bracket]"}',)

Expected Output: True

Explanation: Brackets inside strings are ignored.

Input: ('{"x":"a\\"b"}',)

Expected Output: True

Explanation: Escaped quotes do not end the string.

Input: ('abc',)

Expected Output: False

Explanation: The text must have matching outer brackets.

Hints

Track strings separately from brackets.
Use a stack for bracket nesting.

Quick Overview

This question evaluates parsing and string-processing skills, focusing on structural validation of JSON-like text including matching and nesting of brackets and correct handling of quoted strings with escape sequences.