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DSA 450

Full syllabus coverage. Every topic, every pattern, enough repetition that recall becomes automatic.

215h of work left3 per day to finish in 24 weeks450 problems
Easy
0
of 80
Medium
0
of 291
Hard
0
of 79
By topic
Arrays0/32
Strings0/36
Hashing0/9
Sorting0/5
Binary Search0/22
Two Pointers0/11
Sliding Window0/11
Prefix Sum0/9
Matrix0/9
Intervals0/11
Linked List0/24
Stacks & Queues0/22
Trees0/35
Binary Search Tree0/15
Heap / Priority Queue0/12
Graphs0/36
Greedy0/16
Dynamic Programming0/54
Recursion & Backtracking0/19
Tries0/8
Bit Manipulation0/14
Math & Number Theory0/11
Design (LLD)0/20
Advanced0/9
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0 / 450 solved
Arrays0 / 32
1
Best Time to Buy and Sell Stock
EArrays
2
Longest Consecutive Sequence
MArrays
3
Maximum Subarray
MArrays
4
Product of Array Except Self
MArrays
5
Contains Duplicate
EArrays
6
Maximum Product Subarray
MArrays
7
Find the Duplicate Number
MArrays
8
Majority Element
EArrays
9
Next Permutation
MArrays
10
Rotate Array
MArrays
11
Best Time to Buy and Sell Stock II
MArrays
12
First Missing Positive
HArrays
13
Find All Duplicates in an Array
MArrays
14
Find All Numbers Disappeared in an Array
EArrays
15
Best Time to Buy and Sell Stock III
HArrays
16
Count Inversions
HArrays
17
Maximum Points You Can Obtain from Cards
MArrays
18
Maximum Sum Circular Subarray
MArrays
19
Pascals Triangle
EArrays
20
Plus One
EArrays
21
Subarray Sums Divisible by K
MArrays
22
Boats to Save People
MArrays
23
Chocolate Distribution Problem
EArrays
24
Majority Element II
MArrays
25
Max Consecutive Ones
EArrays
26
Median in a Row-wise Sorted Matrix
HArrays
27
Merge Two Sorted Arrays Without Extra Space
HArrays
28
Minimize the Heights II
MArrays
29
Minimum Swaps to Sort
MArrays
30
Rearrange Array Alternately
MArrays
31
Remove Element
EArrays
32
Set Mismatch
EArrays
Strings0 / 36
1
Group Anagrams
MStrings
2
Longest Palindromic Substring
MStrings
3
Palindromic Substrings
MStrings
4
Valid Anagram
EStrings
5
Valid Palindrome
EStrings
6
Find All Anagrams in a String
MStrings
7
Reverse Words in a String
MStrings
8
Roman to Integer
EStrings
9
String to Integer (atoi)
MStrings
10
Valid Palindrome II
EStrings
11
Find the Index of the First Occurrence in a String
EStrings
12
First Unique Character in a String
EStrings
13
Isomorphic Strings
EStrings
14
Longest Common Prefix
EStrings
15
Add Binary
EStrings
16
Custom Sort String
MStrings
17
Integer to Roman
MStrings
18
KMP Pattern Matching
HStrings
19
Multiply Strings
MStrings
20
Sort Characters By Frequency
MStrings
21
String Compression
MStrings
22
Text Justification
HStrings
23
Compare Version Numbers
MStrings
24
Count and Say
MStrings
25
Excel Sheet Column Title
EStrings
26
Group Shifted Stringspremium
MStrings
27
Longest Duplicate Substring
HStrings
28
Longest Palindrome
EStrings
29
Longest Repeating Subsequence
MStrings
30
Minimum Characters to Add for Palindrome
MStrings
31
One Edit Distancepremium
MStrings
32
Rabin-Karp Substring Search
MStrings
33
Ransom Note
EStrings
34
Repeated Substring Pattern
EStrings
35
Shortest Palindrome
HStrings
36
Zigzag Conversion
MStrings
Hashing0 / 9
1
Two Sum
EHashing
2
Subarray Sum Equals K
MHashing
3
Happy Number
EHashing
4
Continuous Subarray Sum
MHashing
5
Top K Frequent Words
MHashing
6
Valid Sudoku
MHashing
7
4Sum II
MHashing
8
Intersection of Two Arrays II
EHashing
9
Max Points on a Line
HHashing
Sorting0 / 5
1
Implement Merge Sort
MSorting
2
Implement Quick Sort
MSorting
3
Largest Number
MSorting
4
Kth Smallest Element
MSorting
5
H-Index
MSorting
Binary Search0 / 22
1
Search in Rotated Sorted Array
MBinary Search
2
Find Minimum in Rotated Sorted Array
MBinary Search
3
Binary Search
EBinary Search
4
Find First and Last Position of Element in Sorted Array
MBinary Search
5
Find Peak Element
MBinary Search
6
Koko Eating Bananas
MBinary Search
7
Median of Two Sorted Arrays
HBinary Search
8
Allocate Minimum Number of Pages
HBinary Search
9
Capacity To Ship Packages Within D Days
MBinary Search
10
Aggressive Cows
HBinary Search
11
Kth Smallest Element in a Sorted Matrix
MBinary Search
12
K-th Element of Two Sorted Arrays
HBinary Search
13
Search in Rotated Sorted Array II
MBinary Search
14
Search Insert Position
EBinary Search
15
Single Element in a Sorted Array
MBinary Search
16
Split Array Largest Sum
HBinary Search
17
Sqrt(x)
EBinary Search
18
Find Minimum in Rotated Sorted Array II
HBinary Search
19
Minimum Number of Days to Make m Bouquets
MBinary Search
20
Nth Root of a Number
MBinary Search
21
Peak Index in a Mountain Array
MBinary Search
22
Search in an Infinite Sorted Array
MBinary Search
Two Pointers0 / 11
1
3Sum
MTwo Pointers
2
Container With Most Water
MTwo Pointers
3
Trapping Rain Water
HTwo Pointers
4
Merge Sorted Array
ETwo Pointers
5
Move Zeroes
ETwo Pointers
6
Sort Colors
MTwo Pointers
7
Two Sum II - Input Array Is Sorted
MTwo Pointers
8
Remove Duplicates from Sorted Array
ETwo Pointers
9
3Sum Closest
MTwo Pointers
10
4Sum
MTwo Pointers
11
Squares of a Sorted Array
ETwo Pointers
Sliding Window0 / 11
1
Longest Substring Without Repeating Characters
MSliding Window
2
Minimum Window Substring
HSliding Window
3
Longest Repeating Character Replacement
MSliding Window
4
Sliding Window Maximum
HSliding Window
5
Longest Substring with At Most K Distinct Characterspremium
MSliding Window
6
Max Consecutive Ones III
MSliding Window
7
Minimum Size Subarray Sum
MSliding Window
8
Permutation in String
MSliding Window
9
Fruit Into Baskets
MSliding Window
10
Count Number of Nice Subarrays
MSliding Window
11
Minimum Window Subsequencepremium
HSliding Window
Prefix Sum0 / 9
1
Contiguous Array
MPrefix Sum
2
Longest Subarray with Sum K
MPrefix Sum
3
Find Pivot Index
EPrefix Sum
4
Car Pooling
MPrefix Sum
5
Count Subarrays with Given XOR
HPrefix Sum
6
Corporate Flight Bookings
MPrefix Sum
7
Maximum Size Subarray Sum Equals kpremium
MPrefix Sum
8
Number of Submatrices That Sum to Target
HPrefix Sum
9
Range Sum Query 2D - Immutable
MPrefix Sum
Matrix0 / 9
1
Rotate Image
MMatrix
2
Spiral Matrix
MMatrix
3
Word Search
MMatrix
4
Set Matrix Zeroes
MMatrix
5
Search a 2D Matrix
MMatrix
6
Game of Life
MMatrix
7
Search a 2D Matrix II
MMatrix
8
Diagonal Traverse
MMatrix
9
Row with Maximum Number of Ones
MMatrix
Intervals0 / 11
1
Meeting Rooms IIpremium
MIntervals
2
Merge Intervals
MIntervals
3
Insert Interval
MIntervals
4
Meeting Roomspremium
EIntervals
5
Non-overlapping Intervals
MIntervals
6
Interval List Intersections
MIntervals
7
Employee Free Timepremium
HIntervals
8
Minimum Number of Arrows to Burst Balloons
MIntervals
9
The Skyline Problem
HIntervals
10
Maximum Length of Pair Chain
MIntervals
11
My Calendar I
MIntervals
Linked List0 / 24
1
Linked List Cycle
ELinked List
2
Merge k Sorted Lists
HLinked List
3
Merge Two Sorted Lists
ELinked List
4
Remove Nth Node From End of List
MLinked List
5
Reverse Linked List
ELinked List
6
Reorder List
MLinked List
7
Add Two Numbers
MLinked List
8
Copy List with Random Pointer
MLinked List
9
Intersection of Two Linked Lists
ELinked List
10
Linked List Cycle II
MLinked List
11
Palindrome Linked List
ELinked List
12
Reverse Nodes in k-Group
HLinked List
13
Reverse Linked List II
MLinked List
14
Sort List
MLinked List
15
Add Two Numbers II
MLinked List
16
Flatten a Multilevel Doubly Linked List
MLinked List
17
Flattening a Linked List
MLinked List
18
Middle of the Linked List
ELinked List
19
Remove Duplicates from Sorted List II
MLinked List
20
Rotate List
MLinked List
21
Swap Nodes in Pairs
MLinked List
22
Delete Node in a Linked List
MLinked List
23
Odd Even Linked List
MLinked List
24
Partition List
MLinked List
Stacks & Queues0 / 22
1
Valid Parentheses
EStacks & Queues
2
Largest Rectangle in Histogram
HStacks & Queues
3
Min Stack
MStacks & Queues
4
Daily Temperatures
MStacks & Queues
5
Evaluate Reverse Polish Notation
MStacks & Queues
6
Car Fleet
MStacks & Queues
7
Asteroid Collision
MStacks & Queues
8
Basic Calculator II
MStacks & Queues
9
Decode String
MStacks & Queues
10
Longest Valid Parentheses
HStacks & Queues
11
Simplify Path
MStacks & Queues
12
Maximal Rectangle
HStacks & Queues
13
The Celebrity Problem
MStacks & Queues
14
Basic Calculator
HStacks & Queues
15
Next Greater Element I
EStacks & Queues
16
Next Greater Element II
MStacks & Queues
17
Online Stock Span
MStacks & Queues
18
Remove All Adjacent Duplicates in String II
MStacks & Queues
19
Remove K Digits
MStacks & Queues
20
Sum of Subarray Minimums
MStacks & Queues
21
First Negative Integer in Every Window of Size K
MStacks & Queues
22
Implement Stack with getMin in O(1) Space
HStacks & Queues
Trees0 / 35
1
Binary Tree Level Order Traversal
MTrees
2
Binary Tree Maximum Path Sum
HTrees
3
Invert Binary Tree
ETrees
4
Maximum Depth of Binary Tree
ETrees
5
Serialize and Deserialize Binary Tree
HTrees
6
Construct Binary Tree from Preorder and Inorder Traversal
MTrees
7
Same Tree
ETrees
8
Subtree of Another Tree
ETrees
9
Binary Tree Right Side View
MTrees
10
Diameter of Binary Tree
ETrees
11
Lowest Common Ancestor of a Binary Tree
MTrees
12
Balanced Binary Tree
ETrees
13
Binary Tree Inorder Traversal
ETrees
14
Count Good Nodes in Binary Tree
MTrees
15
All Nodes Distance K in Binary Tree
MTrees
16
Binary Tree Zigzag Level Order Traversal
MTrees
17
Flatten Binary Tree to Linked List
MTrees
18
Path Sum III
MTrees
19
Symmetric Tree
ETrees
20
Vertical Order Traversal of a Binary Tree
HTrees
21
Binary Tree Postorder Traversal
ETrees
22
Binary Tree Preorder Traversal
ETrees
23
Boundary Traversal of Binary Tree
MTrees
24
Construct Binary Tree from Inorder and Postorder Traversal
MTrees
25
House Robber III
MTrees
26
Maximum Width of Binary Tree
MTrees
27
Path Sum II
MTrees
28
Populating Next Right Pointers in Each Node
MTrees
29
Top View of Binary Tree
MTrees
30
Binary Tree Cameras
HTrees
31
Bottom View of Binary Tree
MTrees
32
Burning Tree
HTrees
33
Children Sum Property
MTrees
34
Morris Inorder Traversal
HTrees
35
Diameter of N-Ary Treepremium
MTrees
Binary Search Tree0 / 15
1
Kth Smallest Element in a BST
MBinary Search Tree
2
Validate Binary Search Tree
MBinary Search Tree
3
Lowest Common Ancestor of a Binary Search Tree
MBinary Search Tree
4
Binary Search Tree Iterator
MBinary Search Tree
5
Delete Node in a BST
MBinary Search Tree
6
Inorder Successor in BSTpremium
MBinary Search Tree
7
Convert Sorted Array to Binary Search Tree
EBinary Search Tree
8
Insert into a Binary Search Tree
MBinary Search Tree
9
Largest BST in a Binary Tree
HBinary Search Tree
10
Recover Binary Search Tree
MBinary Search Tree
11
Search in a Binary Search Tree
EBinary Search Tree
12
Two Sum IV - Input is a BST
EBinary Search Tree
13
Floor and Ceil in a BST
EBinary Search Tree
14
Kth Largest Element in BST
MBinary Search Tree
15
Predecessor and Successor in BST
MBinary Search Tree
Heap / Priority Queue0 / 12
1
Find Median from Data Stream
HHeap / Priority Queue
2
Top K Frequent Elements
MHeap / Priority Queue
3
K Closest Points to Origin
MHeap / Priority Queue
4
Kth Largest Element in an Array
MHeap / Priority Queue
5
Task Scheduler
MHeap / Priority Queue
6
Reorganize String
MHeap / Priority Queue
7
Implement a Binary Heap
MHeap / Priority Queue
8
Kth Largest Element in a Stream
EHeap / Priority Queue
9
Find K Pairs with Smallest Sums
MHeap / Priority Queue
10
Merge K Sorted Arrays
MHeap / Priority Queue
11
Minimum Cost of Ropes
EHeap / Priority Queue
12
IPO
HHeap / Priority Queue
Graphs0 / 36
1
Clone Graph
MGraphs
2
Course Schedule
MGraphs
3
Number of Islands
MGraphs
4
Alien Dictionarypremium
HGraphs
5
Graph Valid Treepremium
MGraphs
6
Number of Connected Components in an Undirected Graphpremium
MGraphs
7
Pacific Atlantic Water Flow
MGraphs
8
Course Schedule II
MGraphs
9
Rotting Oranges
MGraphs
10
Cheapest Flights Within K Stops
MGraphs
11
Longest Increasing Path in a Matrix
HGraphs
12
Min Cost to Connect All Points
MGraphs
13
Network Delay Time
MGraphs
14
Redundant Connection
MGraphs
15
Word Ladder
HGraphs
16
Reconstruct Itinerary
HGraphs
17
Swim in Rising Water
HGraphs
18
Walls and Gatespremium
MGraphs
19
01 Matrix
MGraphs
20
Accounts Merge
MGraphs
21
Detect Cycle in a Directed Graph
MGraphs
22
Detect Cycle in an Undirected Graph
MGraphs
23
Evaluate Division
MGraphs
24
Is Graph Bipartite
MGraphs
25
Number of Provinces
MGraphs
26
Surrounded Regions
MGraphs
27
Bellman-Ford Algorithm
MGraphs
28
Floyd Warshall Algorithm
MGraphs
29
Path With Minimum Effort
MGraphs
30
Shortest Path in Binary Matrix
MGraphs
31
Word Ladder II
HGraphs
32
Find Eventual Safe States
MGraphs
33
Making A Large Island
HGraphs
34
Minimum Genetic Mutation
MGraphs
35
Number of Enclaves
MGraphs
36
Number of Operations to Make Network Connected
MGraphs
Greedy0 / 16
1
Jump Game
MGreedy
2
Gas Station
MGreedy
3
Jump Game II
MGreedy
4
Partition Labels
MGreedy
5
Hand of Straights
MGreedy
6
Job Sequencing Problem
MGreedy
7
Minimum Platforms
MGreedy
8
N Meetings in One Room
EGreedy
9
Candy
HGreedy
10
Fractional Knapsack
MGreedy
11
Two City Scheduling
MGreedy
12
Valid Parenthesis String
MGreedy
13
Assign Cookies
EGreedy
14
Lemonade Change
EGreedy
15
Merge Triplets to Form Target Triplet
MGreedy
16
Queue Reconstruction by Height
MGreedy
Dynamic Programming0 / 54
1
Climbing Stairs
EDynamic Programming
2
Coin Change
MDynamic Programming
3
Decode Ways
MDynamic Programming
4
House Robber
MDynamic Programming
5
Longest Common Subsequence
MDynamic Programming
6
Longest Increasing Subsequence
MDynamic Programming
7
Unique Paths
MDynamic Programming
8
Word Break
MDynamic Programming
9
House Robber II
MDynamic Programming
10
Combination Sum IV
MDynamic Programming
11
0/1 Knapsack
MDynamic Programming
12
Edit Distance
MDynamic Programming
13
Partition Equal Subset Sum
MDynamic Programming
14
Best Time to Buy and Sell Stock with Cooldown
MDynamic Programming
15
Coin Change II
MDynamic Programming
16
Minimum Path Sum
MDynamic Programming
17
Target Sum
MDynamic Programming
18
Min Cost Climbing Stairs
EDynamic Programming
19
Maximal Square
MDynamic Programming
20
Regular Expression Matching
HDynamic Programming
21
Wildcard Matching
HDynamic Programming
22
Best Time to Buy and Sell Stock IV
HDynamic Programming
23
Burst Balloons
HDynamic Programming
24
Distinct Subsequences
HDynamic Programming
25
Interleaving String
MDynamic Programming
26
Longest Palindromic Subsequence
MDynamic Programming
27
Matrix Chain Multiplication
HDynamic Programming
28
Perfect Sum Problem
MDynamic Programming
29
Best Time to Buy and Sell Stock with Transaction Fee
MDynamic Programming
30
Maximum Profit in Job Scheduling
HDynamic Programming
31
Minimum Sum Partition
HDynamic Programming
32
Palindrome Partitioning II
HDynamic Programming
33
Partition to K Equal Sum Subsets
MDynamic Programming
34
Perfect Squares
MDynamic Programming
35
Rod Cutting
MDynamic Programming
36
Russian Doll Envelopes
HDynamic Programming
37
Triangle
MDynamic Programming
38
Unbounded Knapsack
MDynamic Programming
39
Unique Paths II
MDynamic Programming
40
Word Break II
HDynamic Programming
41
Cherry Pickup II
HDynamic Programming
42
Count Square Submatrices with All Ones
MDynamic Programming
43
Dungeon Game
HDynamic Programming
44
Frog Jump
HDynamic Programming
45
Integer Break
MDynamic Programming
46
Knight Probability in Chessboard
MDynamic Programming
47
Longest Arithmetic Subsequence
MDynamic Programming
48
Longest Bitonic Subsequence
MDynamic Programming
49
Minimum Falling Path Sum
MDynamic Programming
50
Minimum Insertion Steps to Make a String Palindrome
HDynamic Programming
51
Number of Dice Rolls With Target Sum
MDynamic Programming
52
Number of Longest Increasing Subsequence
MDynamic Programming
53
Ones and Zeroes
MDynamic Programming
54
Shortest Common Supersequence
HDynamic Programming
Recursion & Backtracking0 / 19
1
Combination Sum
MRecursion & Backtracking
2
Generate Parentheses
MRecursion & Backtracking
3
Letter Combinations of a Phone Number
MRecursion & Backtracking
4
Permutations
MRecursion & Backtracking
5
Subsets
MRecursion & Backtracking
6
Combination Sum II
MRecursion & Backtracking
7
N-Queens
HRecursion & Backtracking
8
Palindrome Partitioning
MRecursion & Backtracking
9
Subsets II
MRecursion & Backtracking
10
Sudoku Solver
HRecursion & Backtracking
11
Combinations
MRecursion & Backtracking
12
M-Coloring Problem
MRecursion & Backtracking
13
Permutation Sequence
HRecursion & Backtracking
14
Rat in a Maze Problem
MRecursion & Backtracking
15
Permutations II
MRecursion & Backtracking
16
Combination Sum III
MRecursion & Backtracking
17
Expression Add Operators
HRecursion & Backtracking
18
Knight Walk
MRecursion & Backtracking
19
Subset Sums
MRecursion & Backtracking
Tries0 / 8
1
Implement Trie (Prefix Tree)
MTries
2
Design Add and Search Words Data Structure
MTries
3
Word Search II
HTries
4
Search Suggestions System
MTries
5
Maximum XOR of Two Numbers in an Array
MTries
6
Count Distinct Substrings
HTries
7
Phone Directory
MTries
8
Replace Words
MTries
Bit Manipulation0 / 14
1
Counting Bits
EBit Manipulation
2
Missing Number
EBit Manipulation
3
Number of 1 Bits
EBit Manipulation
4
Reverse Bits
EBit Manipulation
5
Single Number
EBit Manipulation
6
Sum of Two Integers
MBit Manipulation
7
Divide Two Integers
MBit Manipulation
8
Power of Two
EBit Manipulation
9
Single Number II
MBit Manipulation
10
Bitwise AND of Numbers Range
MBit Manipulation
11
Gray Code
MBit Manipulation
12
Minimum Bit Flips to Convert Number
EBit Manipulation
13
Single Number III
MBit Manipulation
14
XOR of Numbers in Range
MBit Manipulation
Math & Number Theory0 / 11
1
Pow(x, n)
MMath & Number Theory
2
Reverse Integer
MMath & Number Theory
3
Count Primes
MMath & Number Theory
4
GCD of Two Numbers
EMath & Number Theory
5
Sieve of Eratosthenes
MMath & Number Theory
6
Palindrome Number
EMath & Number Theory
7
Excel Sheet Column Number
EMath & Number Theory
8
Factorial Trailing Zeroes
MMath & Number Theory
9
Fizz Buzz
EMath & Number Theory
10
Josephus Problem
MMath & Number Theory
11
Modular Exponentiation
MMath & Number Theory
Design (LLD)0 / 20
1
Encode and Decode Stringspremium
MDesign (LLD)
2
LRU Cache
MDesign (LLD)
3
Time Based Key-Value Store
MDesign (LLD)
4
Design Twitter
MDesign (LLD)
5
Implement Queue using Stacks
EDesign (LLD)
6
Insert Delete GetRandom O(1)
MDesign (LLD)
7
Random Pick with Weight
MDesign (LLD)
8
Design HashMap
EDesign (LLD)
9
Design Hit Counterpremium
MDesign (LLD)
10
LFU Cache
HDesign (LLD)
11
Range Sum Query - Immutable
EDesign (LLD)
12
All O(1) Data Structure
HDesign (LLD)
13
Design Circular Queue
MDesign (LLD)
14
Design In-Memory File Systempremium
HDesign (LLD)
15
Design Linked List
MDesign (LLD)
16
Design Tic-Tac-Toepremium
MDesign (LLD)
17
Design Underground System
MDesign (LLD)
18
Implement Stack using Queues
EDesign (LLD)
19
Logger Rate Limiterpremium
EDesign (LLD)
20
Shuffle an Array
MDesign (LLD)
Advanced0 / 9
1
Minimum Spanning Tree (Kruskal)
MAdvanced
2
Union-Find with Rank and Path Compression
MAdvanced
3
Range Sum Query - Mutable
MAdvanced
4
Bridges in a Graph (Tarjan)
HAdvanced
5
Count of Smaller Numbers After Self
HAdvanced
6
Articulation Points
HAdvanced
7
Lowest Common Ancestor using Binary Lifting
HAdvanced
8
Range Minimum Query (Sparse Table)
HAdvanced
9
Strongly Connected Components (Kosaraju)
HAdvanced