Day 107 – Decode the String (k[encoded_string] Format) Cracked the nested code 🔐 by decoding strings like 3[a2[c]] ➝ accaccacc! Used a stack to manage multipliers and substrings efficiently. #gfg160 @geeksforgeeks

Day 106 – Postfix Evaluation (Reverse Polish Notation) Mastered the art of evaluating expressions without brackets! 🧮 Used a stack to process operands and operators in postfix order. #gfg160 @geeksforgeeks

Day 105 – Get Min from Stack (O(1) Time & Space) Not your ordinary stack! 🧠 Designed a smart stack where getMin(), push(), and pop() all run in constant time without using extra space. The trick? Encoding the minimum cleverly during push! #geekstreak2025 #gfg160 #stackmagic

Day 104 – Max of Min for Every Window Size Solved the tricky one where for every window size from 1 to n, I found the maximum of minimums using stacks and a clever preprocessing trick. #geekstreak2025 #gfg160 #stackchallenge #windowmagic @geeksforgeeks

Day 103 – Maximum Rectangular Area in a Histogram Tackled one of the classic stack problems! 📐📊 Found the largest rectangular area under the histogram using a monotonic stack in O(n) time. #geekstreak2025 #gfg160 #stackmagic @geeksforgeeks

Day 102 – Stock Span Problem Applied stack-based approach to calculate span efficiently—solved in linear time with real-time comparisons! 📊📉 #geekstreak2025 #gfg160 @geeksforgeeks

Day 101 – Next Greater Element Used a monotonic stack to efficiently find the next greater for each element—linear time, clean logic! 📈📦 #geekstreak2025 #gfg160 @geeksforgeeks

Day 100 – Longest Valid Parentheses Wrapped up the 100-day streak with a challenging one! Solved the Longest Valid Parentheses problem using stack —mastered the balance between logic and precision. #gfg160 challenge! 💯🔥 #geekstreak2025 @geeksforgeeks

Day 99 – Parenthesis Checker Used a stack to validate balanced parentheses—classic problem, evergreen logic! ✅🔁 #geekstreak2025 #gfg160 @geeksforgeeks

Day 98 – Find Median in a Stream Maintained two heaps to dynamically track the median—balanced and efficient streaming solution! ⚖️📊 #geekstreak2025 #gfg160 @geeksforgeeks

Day 97 – Merge K Sorted Linked Lists Merged all lists using a Min-Heap for efficient k-way merging—clean, scalable, and optimal! 🔗📥 #geekstreak2025 #gfg160 @geeksforgeeks

Day 96 – K Closest Points to Origin Solved using Max-Heap to keep the nearest points—geometry meets heaps for optimal selection! 📍📉 #geekstreak2025 #gfg160 @geeksforgeeks

Day 95 – K Largest Elements in Array Used a Min-Heap to efficiently track the top K elements—priority queue at its best! 📊🔼 #geekstreak2025 #gfg160 @geeksforgeeks

Day 94 – Serialize & Deserialize Binary Tree Used preorder traversal to encode and decode the tree—nailed recursive reconstruction with precision! 🔁🌲 #geekstreak2025 #gfg160 @geeksforgeeks

Day 93 – Lowest Common Ancestor (LCA) Traced paths from root to nodes and found their split point—recursion made it clean and efficient! 🌳🔗 #geekstreak2025 #gfg160 @geeksforgeeks

Day 92 – Fix Swapped Nodes in BST Identified and corrected misplaced nodes using Morris Traversal—space-optimized recovery without recursion or stack! 🔧🌳 #geekstreak2025 #gfg160 @geeksforgeeks

Day 91 – Pair Sum in BST Solved using recursion and DFS with a HashSet—combined depth-first search with smart lookup! 🔍🌳 #geekstreak2025 #gfg160 @geeksforgeeks

Day 90 – Kth Smallest in BST Inorder traversal to the rescue—retrieved the Kth smallest with sorted precision! 📉🌳 #geekstreak2025 #gfg160 @geeksforgeeks

Day 89 – Check for BST Verified the BST property using min-max range recursion—ensured every node was in its place! ✅🌳 #geekstreak2025 #gfg160 @geeksforgeeks

Day 88 – K Sum Paths in Binary Tree Explored all paths to count those with sum K—solved with backtracking and path tracking! 🧠🌲 #geekstreak2025 #gfg160 @geeksforgeeks