🎯 Sliding Window Technique: Efficient String & Array Pattern for Frontend Interviews
Category: dsa
Difficulty: hard
Interview Importance: 🔴 Critical — This technique appears in 35% of frontend coding interviews for substring, subarray, and data stream problems. Essential for optimizing O(n²) brute force solutions to O(n) linear time. 1️⃣ What is the Sliding Window Technique? The Sliding Window Technique is an algorithmic pattern that maintains a "window" (contiguous sequence) over an array or string. The window slides through the data structure by adding elements on one end and removing from the other, allowing efficient computation without recalculating everything from scratch. Visual Representation: [code example] Real-World Analogy: Think of it like a camera viewfinder moving across a landscape. Instead of taking a new photo for every possible view (expensive), you slide the viewfinder smoothly, only adjusting what enters and exits the frame. This is exactly how video streaming buffers work in frontend applications! 2️⃣ Why Use the Sliding Window Technique? Without Sliding Window Benefit O(n³) check all substrings 1000x faster for 1000 chars Max sum of k elements O(n) maintain sum O(nm) compare each window Optimal for pattern matching Find all substrings of length k O(n) slide indices O(n²) nested checks Real-time processing |...