LeetCode 560: Subarray Sum Equals K - Beginner Friendly & Most Asked MAANG Question

🚀 LeetCode 560: Subarray Sum Equals K | Beginner Friendly & Most Asked FAANG Question Struggling with LeetCode 560: Subarray Sum Equals K? You're not alone! 👋 This is one of the most frequently asked coding interview questions at top tech companies like Google, Meta, Amazon, Microsoft, and Apple — and it's totally solvable even if you're new to algorithms! In this beginner-friendly tutorial, we break down the optimal O(n) Time solution using Prefix Sum + HashMap — the elegant trick MAANG interviewers actually want to see. No more confusion about nested loops or brute force. We explain everything step-by-step, with visuals, dry runs, and clean code — so you can walk into your next interview with confidence. 💪 🔍 Problem Overview: LeetCode 560 - Subarray Sum Equals K Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k. A subarray is a contiguous non-empty sequence of elements within an array. The brute force approach takes O(n²), but we need a smarter O(n) approach using cumulative sums. That's where the magic happens. ✨ 🎯 What You'll Master in This Beginner-Friendly Tutorial: ✅ Why brute force and nested loops FAIL on large inputs (TLE) ✅ How to use Prefix Sum to calculate subarray sums in O(1) ✅ Step-by-step walkthrough of the HashMap technique — no advanced math needed! ✅ Why current_sum - k tells us if a valid subarray exists (simple proof with diagrams) ✅ Clean, production-ready code in Python, Java, and C++ ✅ Time Complexity: O(n) | Space Complexity: O(n) — explained simply ✅ Common pitfalls & edge cases interviewers love to test (negative numbers, zeros) ✅ How to communicate this solution clearly in a real FAANG interview ⏱️ Video Chapters (Jump to Any Section): 0:00 - Intro: What we'll solve today 🎯 1:02 - Question Explanation: LeetCode 560 problem statement + constraints 2:55 - Answer Explanation: The core intuition behind Prefix Sum & HashMap 6:45 - Pseudo Code Explanation: Step-by-step logic before coding 8:55 - Debugging: Common mistakes & how to fix them 🐛 13:56 - Code Writing: Clean implementation (Python/Java/C++) 15:45 - Test Cases Running: Verify solution with edge cases ✅ 🔗 Essential Resources & Links: 📌 Problem Link: https://leetcode.com/problems/subarray-sum-equals-k/ 📌 Complete Code (Python/Java/C++): [Coming Soon — Subscribe for Updates!] 📌 FULL DSA INTERVIEW PLAYLIST (Beginner to MAANG): https://youtu.be/gTHFdRI-wso?si=kRdi2kDO9lec9z98 💬 Connect With Me For Daily Beginner-Friendly Coding Tips: 📩 Email: [email protected] 📸 Instagram: https://www.instagram.com/infotechiezz/ 💼 LinkedIn: https://www.linkedin.com/in/infotechiezz/ ▶️ YouTube: https://www.youtube.com/@InfoTechiezz 💬 WhatsApp Channel: https://www.whatsapp.com/channel/0029Vb7QJZG8fewpER7N8U0V 🐦 X (Twitter): https://x.com/infotechiezz LeetCode 560 solution beginner, Subarray Sum Equals K easy explanation, Prefix Sum algorithm for beginners, HashMap technique LeetCode simple, O(n) time solution subarray sum beginner, FAANG interview questions for beginners, Google coding interview easy, Meta beginner coding problems, Amazon SDE1 interview prep, Microsoft beginner technical questions, Apple coding challenges simple, array subarray detection tutorial, cumulative sum explained, coding interview patterns for beginners, data structures and algorithms beginner tutorial, Python LeetCode solutions easy, Java DSA interview prep beginner, C++ competitive programming basics, tech job preparation for students, software engineering career start, coding bootcamp help, computer science fundamentals simple, algorithm optimization beginner, interview question walkthrough beginner, Infotechiezz coding tutorial #LeetCode #LeetCode560 #SubarraySumEqualsK #CodingInterview #DSA #DataStructures #Algorithms #PrefixSum #HashMap #ONTime #FAANG #GoogleInterview #MetaInterview #AmazonInterview #MicrosoftInterview #AppleInterview #TechJobs #SoftwareEngineer #Programming #Python #Java #CPlusPlus #CodingTutorial #InterviewPrep #Blind75 #Grind75 #TechCareers #DeveloperLife #CodeNewbie #100DaysOfCode #LearnToCode #ComputerScience #AlgorithmExplained #CodingChallenge #ProblemSolving #TechEducation #YouTubeLearning #Infotechiezz #CodeWithMe #DSAPlaylist #LeetCodeSolutions #InterviewSuccess #CareerGrowth #RemoteWork #BeginnerFriendly #mostaskedquestion 👉 If this beginner-friendly breakdown helped you, please LIKE 👍, SHARE ↗️, and SUBSCRIBE 🔔 to @infotechiezz for more high-impact, easy-to-follow coding interview tutorials! Drop a comment below: "Which problem should I solve next?" — I read every single one. Let's crack FAANG together, one beginner-friendly step at a time! 💙✨