DSA-Patterns-Roadmap

DSA-Patterns-Roadmap

1. Fast and Slow Pointer

Problem

Linked List Cycle II

Remove nth Node from the End of List

Find the Duplicate Number

Palindrome Linked List

2. Overlapping Intervals

Problem

Merge Intervals

Insert Interval

My Calendar II

Minimum Number of Arrows to Burst Balloons

Non-overlapping Intervals

3. Prefix Sum

Problem

Find the middle index in array

Product of array except self

Maximum product subarray

Number of ways to split array

Range Sum Query 2D

4. Sliding Window

Category	Problem
Fixed Size	Maximum Sum Subarray of Size K
	Number of Subarrays having Average Greater or Equal to Threshold
	Repeated DNA sequences
	Permutation in String
	Sliding Subarray Beauty
	Sliding Window Maximum
Variable Size	Longest Substring Without Repeating Characters
	Minimum Size Subarray Sum
	Subarray Product Less Than K
	Max Consecutive Ones
	Fruits Into Baskets
	Count Number of Nice Subarrays
	Minimum Window Substring

5. Two Pointers

Problem

Two Sum II - Input Array is Sorted

Dutch National Flag: Sort Colors

Next Permutation

Bag of Tokens

Container with most water

Trapping Rain Water

6. Cyclic Sort (Index-Based)

Problem

Missing Number

Find Missing Numbers

Set Mismatch

First Missing Positive

7. Reversal of Linked List (In-place)

Problem

Reverse Linked List

Reverse Nodes in k-Group

Swap Nodes in Pairs

8. Matrix Manipulation

Problem

Rotate Image

Spiral Matrix

Set Matrix Zeroes

Game of Life

9. Breadth First Search (BFS)

Problem

Shortest Path in Binary Matrix

Rotten Oranges

As Far From Land as Possible

Word Ladder

10. Depth First Search (DFS)

Problem

Number of Closed Islands

Coloring a Border

DFS from boundary: Number of Enclaves

Shortest time: Time Needed to Inform all Employees

Cyclic Find: Find Eventual Safe States

11. Backtracking

Problem

Permutation II

Combination Sum

Generate Parenthesis

N-Queens

Sudoku Solver

Palindrome Partitioning

Word Search

12. Modified Binary Search

Problem

Search in Rotated Sorted Array

Find Minimum in Rotated Sorted Array

Find Peak Element

Single element in a sorted array

Minimum Time to Arrive on Time

Capacity to Ship Packages within 'd' Days

Koko Eating Bananas

Find in Mountain Array

Median of Two Sorted Arrays

13. Bitwise XOR

Problem

Missing Number

Single Number II

Single Number III

Find the Original array of Prefix XOR

XOR Queries of a Subarray

14. Top 'K' Elements

Problem

Top K Frequent Elements

Kth Largest Element

Ugly Number II

K Closest Points to Origin

15. K-way Merge

Problem

Find K Pairs with Smallest Sums

Kth Smallest Element in a Sorted Matrix

Merge K Sorted Lists

Smallest Range Covering Elements from K Lists

16. Two Heaps

Problem

Find Median from Data Stream

Sliding Window Median

IPO

17. Monotonic Stack

Problem

Next Greater Element II

Next Greater Node in Linked List

Daily Temperatures

Online Stock Span

Maximum Width Ramp

Largest Rectangle in Histogram

18. Trees

Category	Problem
Level Order Traversal	Level order Traversal
	Zigzag Level order Traversal
	Even Odd Tree
	Reverse odd Levels
	Deepest Leaves Sum
	Add one row to Tree
	Maximum width of Binary Tree
	All Nodes Distance K in Binary tree
Tree Construction	Construct BT from Preorder and Inorder
	Construct BT from Postorder and Inorder
	Maximum Binary Tree
	Construct BST from Preorder
Height related	Maximum Depth of BT
	Balanced Binary Tree
	Diameter of Binary Tree
	Minimum Depth of BT
Root to leaf path	Binary Tree Paths
	Path Sum II
	Sum Root to Leaf numbers
	Smallest string starting from Leaf
	Insufficient nodes in root to Leaf
	Pseudo-Palindromic Paths in a Binary Tree
	Binary Tree Maximum Path Sum
Ancestor problem	LCA of Binary Tree
	Maximum difference between node and ancestor
	LCA of deepest leaves
	Kth Ancestor of a Tree Node
Binary Search Tree	Validate BST
	Range Sum of BST
	Minimum Absolute Difference in BST
	Insert into a BST
	LCA of BST

19. Dynamic Programming

Category	Problem
Take / Not take (0/1 Knapsack)	House Robber II
	Target Sum
	Partition Equal Subset Sum
	Ones and Zeroes
	Last Stone Weight II
Infinite Supply	Coin Change
	Coin Change II
	Perfect Squares
	Minimum Cost For Tickets
Longest Increasing Subsequence	Longest Increasing Subsequence
	Largest Divisible Subset
	Maximum Length of Pair Chain
	Number of LIS
	Longest String Chain
DP on Grids	Unique Paths II
	Minimum Path Sum
	Triangle
	Minimum Falling Path Sum
	Maximal Square
	Cherry Pickup
	Dungeon Game
DP on Strings	Longest Common Subsequence
	Longest Palindromic Subsequence
	Palindromic Substrings
	Longest Palindromic Substring
	Edit Distance
	Minimum ASCII Delete Sum for Two Strings
	Distinct Subsequences
	Shortest Common Supersequence
	Wildcard Matching
DP on Stocks	Buy and Sell Stocks II
	Buy and Sell Stocks III
	Buy and Sell Stocks IV
	Buy and Sell Stocks with Cooldown
	Buy and Sell Stocks with Transaction Fee

20. Graphs

Category	Problem
Topological Sort	Course Schedule
	Course Schedule II
	Strange Printer II
	Sequence Reconstruction
	Alien Dictionary
Union-Find	Number of Operations to Make Network Connected
	Redundant Connection
	Accounts Merge
	Satisfiability of Equality Equations

21. Greedy

Problem

Jump Game II

Gas Station

Bag of Tokens

Boats to Save People

Wiggle Subsequence

Car Pooling

Candy

22. Design Data Structure

Problem

Design Twitter

Design Browser History

Design Circular Deque

Snapshot Array

LRU Cache