LeetCode 402 | Remove K Digits 🔥 Monotonic Stack Optimal Solution | MAANG Interview Prep

LeetCode 402 | Remove K Digits 🔥 Monotonic Stack Optimal Solution | MAANG Interview Prep In this video, we’ll solve LeetCode 402 – Remove K Digits, one of the most popular Greedy + Monotonic Stack interview problems. The challenge: remove k digits from a number string to form the smallest possible integer. This problem is a favorite in FAANG/MAANG interviews and has been asked at Amazon, Google, Microsoft, Facebook (Meta), Apple, and Goldman Sachs. If you are preparing for top product-based companies, this question is a must-master. What you’ll learn in this video: 🚀 Intuition behind the greedy approach 🏗️ How monotonic stacks guarantee the smallest result ⚡ Step-by-step dry runs with examples 🐞 Handling tricky edge cases (leading zeros, all digits removed, strictly increasing sequences) 🏆 Optimal time complexity: O(N) solution explained & implemented Timestamps 00:00 Problem Introduction with examples 02:15 Brute Force Idea & why it fails 05:00 Greedy Approach explained 08:30 Monotonic Stack intuition (step-by-step) 13:00 Code walkthrough (clean + interview-friendly) 18:00 Edge cases & pitfalls 21:00 Complexity Analysis & Interview Follow-ups 📌 This is part of the Monotonic Stack Series, continuing from Largest Rectangle in Histogram (LeetCode 84). Mastering this will give you confidence in solving many stack + greedy interview questions. 🔥 If you’re targeting MANG/MAANG interviews, this is one of those high-frequency problems you just can’t skip. 👉 Don’t forget to like, subscribe, and share with your prep buddies — let’s hit 1 Million views together! 💪