EasyNo. 2520
Count the Digits That Divide a Number — LeetCode 2520 Python Solution
- Pattern
- Math and Number Theory
- Topics
- Math
- Reading time
- 2 min
- Source
- leetcode.com
The problem
Given an integer num, return the number of digits in num that divide num. An integer val divides nums if nums % val == 0.
Example
- Input
- num = 7
- Output
- 1
- Explanation
- 7 divides itself, hence the answer is 1.
Python solution
class Solution:
def countDigits(self, num: int) -> int:
ans, x = 0, num
while x:
x, val = divmod(x, 10)
ans += num % val == 0
return ansComplexity
- Time
- O(log 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 2520. Count the Digits That Divide a Number 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 |
|---|---|---|
| 2523 | Closest Prime Numbers in Range | Medium |
| 2525 | Categorize Box According to Criteria | Easy |
| 0002 | Add Two Numbers | Medium |
| 0007 | Reverse Integer | Medium |
| 0009 | Palindrome Number | Easy |
| 0043 | Multiply Strings | Medium |
Frequently asked questions
- How hard is LeetCode 2520. Count the Digits That Divide a Number?
LeetCode 2520. Count the Digits That Divide a Number is rated Easy on LeetCode.
- What is the time complexity of LeetCode 2520. Count the Digits That Divide a Number?
The Python solution on this page runs in O(log num).
- What is the space complexity of LeetCode 2520. Count the Digits That Divide a Number?
The Python solution on this page uses O(1) auxiliary space.
- What topics does LeetCode 2520. Count the Digits That Divide a Number cover?
LeetCode 2520. Count the Digits That Divide a Number is tagged Math on LeetCode.