TOPICS

Below is the classification of problems based on topics, useful while cementing any particular data structure, algorithm or topic.

Array

• 1. Two Sum
• 135. Candy
• 2226. Maximum Candies Allocated to K Children
• 240. Search a 2D Matrix II
• 407. Trapping Rain Water II
• 42. Trapping Rain Water
• 74. Search a 2D Matrix
• 746. Min Cost Climbing Stairs

Backtracking

• 52. N-Queens II

Binary Search

• 2226. Maximum Candies Allocated to K Children
• 240. Search a 2D Matrix II
• 374. Guess Number Higher or Lower
• 74. Search a 2D Matrix

Binary Search Tree

• 703. Kth Largest Element in a Stream

Binary Tree

• 703. Kth Largest Element in a Stream

Bit Manipulation

• 29. Divide Two Integers

Breadth-First Search

• 407. Trapping Rain Water II

Data Stream

• 703. Kth Largest Element in a Stream

Design

• 703. Kth Largest Element in a Stream

Divide and Conquer

• 240. Search a 2D Matrix II

Dynamic Programming

• 42. Trapping Rain Water
• 746. Min Cost Climbing Stairs

Greedy

• 135. Candy

Grind 169

• 1. Two Sum
• 2. Add Two Numbers

Hash Table

• 1. Two Sum
• 3. Longest Substring Without Repeating Characters

Heap (Priority Queue)

• 407. Trapping Rain Water II
• 703. Kth Largest Element in a Stream

Interactive

• 374. Guess Number Higher or Lower

LP

• 3. Composing flight crews
• 4. N Queen

Linked List

• 19. Remove Nth Node From End of List
• 2. Add Two Numbers

MIP

• 1. Mixed Integer Programming
• 3. Composing flight crews
• 4. N Queen

Math

• 2. Add Two Numbers
• 29. Divide Two Integers

Matrix

• 240. Search a 2D Matrix II
• 4. N Queen
• 407. Trapping Rain Water II
• 74. Search a 2D Matrix

Monotonic Stack

• 42. Trapping Rain Water

Recursion

• 2. Add Two Numbers

Sliding Window

• 3. Longest Substring Without Repeating Characters

Stack

• 20. Valid Parentheses
• 42. Trapping Rain Water

String

• 20. Valid Parentheses
• 3. Longest Substring Without Repeating Characters

Tree

• 703. Kth Largest Element in a Stream

Two Pointers

• 19. Remove Nth Node From End of List
• 42. Trapping Rain Water