Convert a Number to Hexadecimal — LeetCode 405 Python Solution

The problem

Given a 32-bit integer num, return a string representing its hexadecimal representation. For negative integers, two’s complement method is used.

Example

Input

num = 26

Output

"1a"

Python solution

class Solution:
    def toHex(self, num: int) -> str:
        if num == 0:
            return '0'
        chars = '0123456789abcdef'
        s = []
        for i in range(7, -1, -1):
            x = (num >> (4 * i)) & 0xF
            if s or x != 0:
                s.append(chars[x])
        return ''.join(s)

Complexity

Pattern: Bit Manipulation

Use XOR, masks and the low-bit trick to replace whole data structures with an integer. LeetCode 405. Convert a Number to Hexadecimal is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Bit Manipulation.

The bit manipulation guide has the Python template for the pattern and the 194 LeetCode problems that use it.

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