🔥 LeetCode 1248: Count Nice Subarrays | Sliding Window (At Most K) Trick for MAANG Interviews!

🔥 LeetCode 1248: Count Nice Subarrays | Sliding Window (At Most K) Trick for MAANG Interviews!

In this video, we solve LeetCode 1248: Count Number of Nice Subarrays using the powerful Sliding Window with At Most K technique — one of the most underrated but effective patterns for subarray counting in FAANG interviews.

Leetcode 930: https://www.youtube.com/watch?v=HCCO82HjI-o
Utilize: https://penpaperpreparation.com/

💡 Problem Summary:
You’re given an integer array and a number k. Count the number of contiguous subarrays that contain exactly k odd numbers.
Instead of brute-force or prefix sums, we use the efficient formula:
🔁 Exactly K = At Most K − At Most (K−1)

🎯 What You’ll Learn:

Full explanation of "at most K" vs "exactly K" subarray counting

Sliding Window implementation using simple two-pointer logic

Clean and reusable pattern you can apply to:

LeetCode 930 (Binary Subarrays With Sum)

LeetCode 1358 (Substrings With All Three Characters)

Longest Substring With Exactly K Unique Characters

Time and space complexity analysis

Real test case dry run

💼 Asked in real interviews at:

Amazon (SDE1/SDE2)

Meta/Facebook DSA rounds

Google OA + Phone Screen

Microsoft (variation-based questions)

📌 Problem Link: https://leetcode.com/problems/count-number-of-nice-subarrays/

🎯 This video is part of: “DSA + Binary Search Playlist for Tech Interviews | Google, Meta, Microsoft Prep”

📢 Whether you're prepping for FAANG interviews or top-tier product companies, this video gives you a reusable trick that you can apply to a wide class of subarray counting problems.

Видео 🔥 LeetCode 1248: Count Nice Subarrays | Sliding Window (At Most K) Trick for MAANG Interviews! канала Pen And Paper