↓Skip to main content

LeetCode

LeetCode 739: Daily Temperatures
·2 mins
LeetCode Daily Medium Array Stack Monotonic-Stack Data-Structures Temperature Waiting-Time
Solving the Daily Temperatures problem using monotonic stack approach
LeetCode 22: Generate Parentheses
·2 mins
LeetCode Daily Medium String Backtracking Recursion Combinatorics Parentheses
Generating all valid parentheses combinations using backtracking approach
LeetCode 20: Valid Parentheses
·2 mins
LeetCode Daily Easy String Stack Data-Structures Parentheses Validation
Solving the Valid Parentheses problem using stack-based approach
LeetCode 155: Min Stack
·2 mins
LeetCode Daily Medium Stack Constant-Time Data-Structures Design Tuple
Implementing a stack with O(1) minimum retrieval using tuple-based approach
LeetCode 150: Evaluate Reverse Polish Notation
·2 mins
LeetCode Daily Medium Stack Data-Structures Expression-Evaluation Math Postfix-Notation Reverse-Polish-Notation
Solving the Reverse Polish Notation evaluation problem using stack-based approach
LeetCode 503: Next Greater Element II (Monotonic Stack)
·2 mins
LeetCode Daily Medium Array Stack Monotonic-Stack Circular-Array
Monotonic stack on a circular array
LeetCode 496: Next Greater Element I (Monotonic Stack)
·2 mins
LeetCode Daily Easy Array Stack Monotonic-Stack Hash-Map Next-Greater-Element
Monotonic decreasing stack over nums2 to build next-greater map; answer queries for nums1.
LeetCode 3439: Reschedule Meetings for Maximum Free Time (Sliding Window)
·3 mins
LeetCode Daily Medium Array Sliding-Window Two-Pointers Intervals
Sliding window over meetings; track total duration in a k-sized window and compute free span between boundaries.
LeetCode 30: Substring with Concatenation of All Words (Brute Force → Counting → Sliding Window)
·3 mins
LeetCode Daily Hard String Sliding-Window Two-Pointers Hash-Map Brute-Force Frequency-Counting
Three approaches: brute force, counting optimization, and sliding window over word-length offsets.
LeetCode 209: Minimum Size Subarray Sum (Sliding Window)
·1 min
LeetCode Daily Medium Array Sliding-Window Two-Pointers Prefix-Sum Binary-Search
Sliding window with two pointers; minimize subarray length where sum ≥ target.
LeetCode 1695: Maximum Erasure Value (Sliding Window)
·1 min
LeetCode Daily Medium Array Sliding-Window Two-Pointers Hash-Set
Sliding window with a set and running sum; two pointers to keep the subarray unique.
LeetCode 1497: Check If Array Pairs Are Divisible by k (Remainder Pairing, Modulo)
·2 mins
LeetCode Daily Medium Array Hash-Map Complement Counting Math Modulo
Remainder pairing with a hash map; handle 0 and k/2 remainders carefully.