Subarray Sum Equals K | Sliding Window Approach in Java | DSA Lecture 4

Welcome to **Code With Rahul Kumawat** 🚀 In this lecture, we will solve an important DSA problem: 👉 **Subarray Sum Equals K** We are given an **unsorted array containing non-negative elements** and a target sum **K (SUM)**. Our task is to check whether there exists a **contiguous subarray** whose sum is equal to the given value. --- ## 📌 Concepts Used: * Sliding Window Technique * Two Pointers Approach * Subarray Problems in Java * Optimization to O(N) solution --- ## 💡 Key Idea: Since all elements are **non-negative**, we can efficiently solve this using the **sliding window method** instead of brute force. We expand the window to increase sum and shrink it when the sum becomes larger than the target. --- ## 🚀 Why this problem is important? * Frequently asked in coding interviews * Builds strong understanding of arrays & pointers * Base concept for advanced DSA problems --- ## 📺 Lecture Series: This is **Lecture 4** of our DSA in Java series with notes. --- 👉 Like 👍 | Share 🔁 | Subscribe 🔔 for more DSA lectures 📌 Channel: Code With Rahul Kumawat