Convert a Number to Hexadecimal

EasyBit Manipulationbit manipulation

Solve this the way you would in the interview: out loud, on a timer, with an AI interviewer asking follow-ups while you code. You get a scored report at the end.

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Problem

Given a 32-bit signed integer num, return its hexadecimal representation as a string. Negative numbers use **32-bit two's complement** (so -1 becomes "ffffffff"). Use lowercase digits 0-9a-f and no leading zeros, except that 0 itself is "0". Build the string yourself — no built-in base-conversion helpers such as hex(), format(..., 'x'), or toString(16).

Examples

Input: num = 26
Output: "1a"
26 = 1 * 16 + 10, and 10 is the digit `a`.
Input: num = -1
Output: "ffffffff"
In 32-bit two's complement, -1 has all 32 bits set.

Constraints

  • -2^31 <= num <= 2^31 - 1

What the interviewer grades

A correct solution is one of five scores. The report also grades problem understanding (did you clarify inputs and edge cases before coding), problem solving, communication while you work, code quality, and testing. See a sample report, or read up on the pattern in the lessons.

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