dsa6 min read
Largest Rectangle in Histogram — Monotonic Stack Masterclass
Solve LeetCode 84 Largest Rectangle in Histogram in O(n) using a monotonic increasing stack. The single most important monotonic stack interview problem at FAANG.
Read →
All Posts
1582 articles
dsa6 min read
Maximal Rectangle — Histogram per Row + Monotonic Stack
Solve LeetCode 85 Maximal Rectangle in O(m times n) by reducing each row to a histogram and applying the monotonic stack. A FAANG hard interview classic.
Read →
dsa8 min read
Basic Calculator — Stack-Based Expression Parsing with Parentheses
Solve LeetCode 224 Basic Calculator with a single-pass stack approach handling +, -, parentheses, and arbitrary whitespace in O(n). A FAANG hard parsing classic.
Read →
dsa6 min read
Max Frequency Stack — Stack of Stacks Indexed by Frequency
Solve LeetCode 895 Maximum Frequency Stack with a layered "stack of stacks" data structure giving O(1) push and pop. A FAANG hard design favorite.
Read →
dsa7 min read
Find Median from Data Stream — Two-Heap Streaming Pattern
Solve LeetCode 295 Find Median from Data Stream with two heaps (max-heap for low half, min-heap for high half) giving O(log n) addNum and O(1) findMedian. A FAANG streaming classic.
Read →
Page 149 of 317