Is Self Dividing Numbers easy or hard?

Self Dividing Numbers is classified as an Easy problem. The main challenge is correctly extracting digits and handling edge cases such as the digit 0, which automatically invalidates the number.

Self Dividing Numbers Python/Java solution

The core logic is identical across languages. Loop from left to right, extract digits using modulo, and check if each digit divides the original number. Python, Java, C++, C#, and JavaScript implementations all follow the same O(n * d) algorithm.

How to solve Self Dividing Numbers in O(n)?

Practically the solution runs in O(n * d) because each number requires digit extraction. However, since d is small (at most 10 digits for typical integer ranges), it behaves close to linear time. The optimized method stops checking digits early when encountering 0 or a non-divisible digit.

What is the best approach for Self Dividing Numbers?

The best approach is digit analysis with early termination. Iterate through the range and extract digits using modulo operations. If a digit is 0 or the number is not divisible by that digit, stop immediately. This keeps the solution simple with O(n * d) time and O(1) space complexity.

Is Self Dividing Numbers asked at Google/Amazon/Meta?

Self Dividing Numbers is generally considered a beginner-level screening problem. It appears in coding assessments and early interview rounds to evaluate basic math reasoning, loops, and digit manipulation rather than advanced algorithms.

What data structure is used in Self Dividing Numbers?

No complex data structures are required. The solution relies on arithmetic operations such as modulo and integer division to extract digits. A simple list or array is used to store the valid self dividing numbers in the result.

What is the time complexity of Self Dividing Numbers?

The time complexity is O(n * d), where n is the size of the range and d is the number of digits in each number (approximately log10(n)). Each number is processed once, and its digits are checked individually using modulo and division operations.

Description Hints 1 Solution Video 8:36

728. Self Dividing Numbers

Easy81.3% acceptance5 companies

A self-dividing number is a number that is divisible by every digit it contains.

For example, 128 is a self-dividing number because 128 % 1 == 0, 128 % 2 == 0, and 128 % 8 == 0.

A self-dividing number is not allowed to contain the digit zero.

Given two integers left and right, return a list of all the self-dividing numbers in the range [left, right] (both inclusive).

Example 1:

Input: left = 1, right = 22
Output: [1,2,3,4,5,6,7,8,9,11,12,15,22]

Example 2:

Input: left = 47, right = 85
Output: [48,55,66,77]

Constraints:

1 <= left <= right <= 10⁴

Asked at 5 companies

Epic Systems

Google Microsoft Amazon Meta

Topics

Math

Hints open one at a time

Hint 1

For each number in the range, check whether it is self dividing by converting that number to a character array (or string in Python), then checking that each digit is nonzero and divides the original number.

8:36

Still stuck?Read 3 approaches, or watch a walkthrough.

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