LeetCode 1109. Corporate Flight Bookings | Prefix Sum & Difference Array Explained.

🚀 In this video, we solve *LeetCode 1109 – Corporate Flight Bookings**, a classic problem that introduces the powerful **Difference Array + Prefix Sum* technique. At first glance, updating every flight in every booking range seems straightforward, but that approach quickly becomes too slow. The key is learning how to perform range updates efficiently and recover the final answer using a prefix sum. 💡 What you'll learn: Why the brute force approach is inefficient The intuition behind Difference Arrays How to perform range updates in O(1) Using Prefix Sum to reconstruct the final array Step-by-step walkthrough of the optimal solution Common patterns where this technique appears 🧠 Key Insight: Instead of updating every element in a range, we only mark where the change starts and where it ends. Once all updates are recorded, a simple prefix sum gives us the final number of seats booked for every flight. We also discuss: Difference Array intuition Prefix Sum reconstruction Time Complexity: *O(N + M)* Space Complexity: *O(N)* This is an important problem because Difference Arrays and Prefix Sums appear frequently in: Range update problems Interval processing Sweep line techniques Competitive programming Coding interviews 🔥 Subscribe for more LeetCode Daily solutions, coding interview preparation, DSA concepts, and contest editorials. #LeetCode #LeetCodeDaily #PrefixSum #DifferenceArray #Arrays #Algorithms #DSA #CodingInterview #ProblemSolving #CompetitiveProgramming