Is Smallest Missing Multiple of K easy or hard?

Smallest Missing Multiple of K is categorized as an Easy problem. The main idea is recognizing that repeated membership checks should use a hash set instead of scanning the array each time.

Smallest Missing Multiple of K Python/Java solution

In Python, use a set to store the array elements and repeatedly check multiples of k. In Java, use a HashSet for constant-time lookups. The same logic works in C++, Go, and TypeScript using their respective hash-based set structures.

How to solve Smallest Missing Multiple of K in O(n)?

Insert every number from the array into a hash set. Start with candidate = k and repeatedly check if the candidate exists in the set. If it exists, increase the candidate by k and continue. The first candidate not found in the set is the smallest missing multiple.

What is the best approach for Smallest Missing Multiple of K?

The most efficient approach uses a hash table (set) combined with enumeration. Insert all array elements into a set, then check multiples of k starting from k. The first multiple not found in the set is the answer. This reduces lookup time to O(1) and results in overall O(n) time complexity.

Is Smallest Missing Multiple of K asked at Google/Amazon/Meta?

Problems involving missing numbers, hash set lookups, and array membership checks appear frequently in interviews at companies like Amazon, Google, and Meta. While the exact problem may vary, the underlying hash table pattern is a common interview topic.

What data structure is used in Smallest Missing Multiple of K?

A hash table (typically implemented as a hash set) is the primary data structure. It allows constant-time membership checks when verifying whether a multiple of k already exists in the array.

What is the time complexity of Smallest Missing Multiple of K?

The optimal solution runs in O(n) time. Building the hash set requires O(n), and checking multiples of k continues until the first missing value is found. In the worst case, if the array contains the first n multiples of k, the enumeration also runs up to O(n).

Description Hints 2 Solution Video 1:47

3718. Smallest Missing Multiple of K

Easy71.5% acceptance

Given an integer array nums and an integer k, return the smallest positive multiple of k that is missing from nums.

A multiple of k is any positive integer divisible by k.

Example 1:

Input: nums = [8,2,3,4,6], k = 2

Output: 10

Explanation:

The multiples of k = 2 are 2, 4, 6, 8, 10, 12... and the smallest multiple missing from nums is 10.

Example 2:

Input: nums = [1,4,7,10,15], k = 5

Output: 5

Explanation:

The multiples of k = 5 are 5, 10, 15, 20... and the smallest multiple missing from nums is 5.

Constraints:

1 <= nums.length <= 100
1 <= nums[i] <= 100
1 <= k <= 100

Topics

Array Hash Table

Hints open one at a time

Hint 1

Add the values in nums to a hash set

Hint 2

Iterate through the positive multiples of k and return the first one not in the hash set

1:47

Still stuck?Read the written solution, or watch a walkthrough.

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1class Solution:
2    def missingMultiple(self, nums: List[int], k: int) -> int:
3        

Starter codePython 3Spaces: 4

Examples

Case 1Case 2

Input

[8,2,3,4,6]
2

Input

[1,4,7,10,15]
5

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