Is Subarray Product Less Than K easy or hard?

Subarray Product Less Than K is classified as a Medium problem on LeetCode. The difficulty comes from recognizing that enumerating all subarrays is unnecessary and that a sliding window can count valid ranges in linear time.

Subarray Product Less Than K Python/Java solution

Most implementations use the same sliding window logic across languages. Maintain two pointers, update the product while expanding the window, shrink when the product exceeds the limit, and accumulate the count using right - left + 1. The algorithm works identically in Python, Java, C++, C#, and JavaScript.

How to solve Subarray Product Less Than K in O(n)?

Use a sliding window with two pointers. Expand the window by moving the right pointer and multiply the new value into the running product. If the product becomes >= k, move the left pointer forward and divide values until the product is valid again. Add right - left + 1 to the result at each step.

What is the best approach for Subarray Product Less Than K?

The sliding window (two pointers) approach is the best solution. Maintain a running product while expanding the right pointer and shrink the window when the product becomes >= k. Each step counts all valid subarrays ending at the current index, resulting in O(n) time and O(1) space.

Is Subarray Product Less Than K asked at Google/Amazon/Meta?

Subarray product and sliding window problems appear frequently in interviews at companies like Amazon, Google, and Meta. The question tests two‑pointer reasoning, window maintenance, and recognizing when a monotonic property allows linear scanning.

What data structure is used in Subarray Product Less Than K?

The problem primarily uses the sliding window technique on an array with two pointers and a running product variable. No additional data structures are required beyond constant extra space.

What is the time complexity of Subarray Product Less Than K?

The optimal sliding window solution runs in O(n) time because each element is added to and removed from the window at most once. The brute force approach takes O(n^2) time since it checks every possible subarray.

Description Hints 1 Solution Video 9:54

713. Subarray Product Less Than K

Medium54.8% acceptance20 companies

Given an array of integers nums and an integer k, return the number of contiguous subarrays where the product of all the elements in the subarray is strictly less than k.

Example 1:

Input: nums = [10,5,2,6], k = 100
Output: 8
Explanation: The 8 subarrays that have product less than 100 are:
[10], [5], [2], [6], [10, 5], [5, 2], [2, 6], [5, 2, 6]
Note that [10, 5, 2] is not included as the product of 100 is not strictly less than k.

Example 2: