Convert 32-bit integer to hexadecimal
Company: Meta
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Onsite
## Problem
Given a 32-bit signed integer `num`, return its **hexadecimal representation** as a string.
## Requirements
- Use **lowercase** letters `a-f`.
- Do **not** include leading zeros (unless the value is exactly zero).
- For **negative** numbers, return the hexadecimal representation of the corresponding **32-bit two's complement** value.
## Input
- Integer `num` in range `[-2^31, 2^31 - 1]`
## Output
- A string containing the hexadecimal representation.
## Examples
- `num = 26` → `"1a"`
- `num = 0` → `"0"`
- `num = -1` → `"ffffffff"`
## Follow-ups (optional)
- Implement without using built-in base conversion utilities (e.g., no `toString(16)` / `format`).
Quick Answer: This question evaluates understanding of integer representation, hexadecimal notation, bitwise operations, and 32-bit two's complement arithmetic. It is commonly asked to assess low-level data representation and edge-case handling within the Coding & Algorithms domain, and it tests practical implementation skills alongside conceptual understanding of binary and base conversion.