EasyNo. 1271LeetCode Premium
Hexspeak — LeetCode 1271 Python Solution
- Pattern
- Math and Number Theory
- Topics
- Math, String
- Reading time
- 2 min
- Source
- leetcode.com
The problem
A decimal number can be converted to its Hexspeak representation by first converting it to an uppercase hexadecimal string, then replacing all occurrences of the digit '0' with the letter 'O', and the digit '1' with the letter 'I'. Such a representation is valid if and only if it consists only of the letters in the set {'A', 'B', 'C', 'D', 'E', 'F', 'I', 'O'}.
Example
- Input
- num = "257"
- Output
- "IOI"
- Explanation
- 257 is 101 in hexadecimal.
Python solution
class Solution:
def toHexspeak 🔒(self, num: str) -> str:
s = set('ABCDEFIO')
t = hex(int(num))[2:].upper().replace('0', 'O').replace('1', 'I')
return t if all(c in s for c in t) else 'ERROR'Complexity
- Time
- O(log n)where n is the size of the decimal number represented by num
- Space · auxiliary
- O(1)
Pattern: Math and Number Theory
Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 1271. Hexspeak is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Math.
The math and number theory guide has the Python template for the pattern and the 485 LeetCode problems that use it.
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 0043 | Multiply Strings | Medium |
| 0168 | Excel Sheet Column Title | Easy |
| 0171 | Excel Sheet Column Number | Easy |
| 0273 | Integer to English Words | Hard |
| 0412 | Fizz Buzz | Easy |
| 0415 | Add Strings | Easy |
Frequently asked questions
- How hard is LeetCode 1271. Hexspeak?
LeetCode 1271. Hexspeak is rated Easy on LeetCode.
- What is the time complexity of LeetCode 1271. Hexspeak?
The Python solution on this page runs in O(log n), where n is the size of the decimal number represented by num.
- What is the space complexity of LeetCode 1271. Hexspeak?
The Python solution on this page uses O(1) auxiliary space.
- What topics does LeetCode 1271. Hexspeak cover?
LeetCode 1271. Hexspeak is tagged Math and String on LeetCode.
- Is LeetCode 1271. Hexspeak a premium problem?
Yes. LeetCode 1271. Hexspeak is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.