Day 24: Validate Binary Search Tree (LeetCode 98) — The Range Trick Everyone Misses! 🔥 скачать в хорошем качестве

Day 24: Validate Binary Search Tree (LeetCode 98) — The Range Trick Everyone Misses! 🔥

🎯 Day 24 of My LeetCode Journey | Validate Binary Search Tree (LeetCode 98) In this video, I solve LeetCode Problem #98 — Validate Binary Search Tree, one of the most asked interview questions at top tech companies! 🚀 Many people get this WRONG because they forget the global constraint rule. I'll show you the RIGHT way using range validation with DFS. 🔗 Problem Link: https://leetcode.com/problems/validat... 📌 PROBLEM SUMMARY: Given the root of a binary tree, determine if it is a valid binary search tree (BST). A valid BST is defined as: The left subtree contains only nodes with keys less than the node's key The right subtree contains only nodes with keys greater than the node's key Both left and right subtrees must also be BSTs ✅ Example 1: Input: root = [2,1,3] Output: true ✅ Example 2: Input: root = [5,1,4,null,null,3,6] Output: false Explanation: The root's value is 5, but its right child's value is 4. ⚠️ COMMON MISTAKE: Many people only check if left less than root less than right at each node, but this is WRONG! You need to track min/max bounds for the entire subtree. 💡 KEY CONCEPTS: ✅ Range Validation (min/max bounds) ✅ DFS with boundary tracking ✅ Global constraint checking (not just local) ✅ Alternative: Inorder traversal approach 📊 COMPLEXITY: • Time: O(n) (visit each node once) • Space: O(h) recursion stack (h = height) 🎓 DIFFICULTY: Medium 🏷️ TOPICS: Tree, Binary Search Tree, Depth-First Search 🔥 WHY THIS VIDEO IS IMPORTANT: This is a top FAANG interview question that trips up many candidates. Master this and you'll ace similar BST problems! 🔔 SUBSCRIBE for daily LeetCode solutions and coding challenges! 👍 SMASH that LIKE button if this helped! 💬 COMMENT your approach or questions below! 📚 MY LEETCODE JOURNEY PLAYLIST:    • Leetcode   🤝 CONNECT WITH ME: • GitHub: https://github.com/ashwinikemshetty • LinkedIn:   / ashwinikemshetty   #LeetCode #ValidateBST #LeetCode98 #Day24 #BST #BinarySearchTree #FAANGInterview #CodingInterview #DSA #Algorithms #100DaysOfCode