Love Babbar DSA Sheet
A well-structured roadmap covering every major DSA concept needed for placements.
By Love Babbar · 430 Problems
Total Problems: 430Difficulty Levels:BasicEasyMediumHard
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Find the Duplicate Number
Merge Intervals
Next Permutation
Best Time to Buy and Sell Stock
Write A Program To Reverse An Array Or String
Maximum And Minimum In An Array
Kth Smallest
Sort 0s, 1s and 2s
Move Negative Numbers Beginning Positive End Constant Extra Space
Union of Arrays with Duplicates
Rotate Array by One
Kadane's Algorithm
Minimize the Heights II
Minimum Jumps
Merge Without Extra Space
Count Inversions
Two sum -Pairs with 0 Sum
Common in 3 Sorted Arrays
Rearrange Array Alternating Positive Negative Items O1 Extra Space
Subarray with 0 sum
Factorials of large numbers
Maximum Product Subarray
Longest Consecutive Subsequence
Given An Array Of Of Size N Finds All The Elements That Appear More Than Nk Times
Maximum Profit By Buying And Selling A Share At Most Twice
Array Subset
Triplet Sum in Array
Trapping Rain Water
Chocolate Distribution Problem
Smallest subarray with sum greater than x
Three way partitioning
Minimum swaps and K together
Palindromic Array
Median of an Array
Median Of Two Sorted Arrays Of Different Sizes
Search a 2D Matrix
Spirally traversing a matrix
Median in a row-wise sorted Matrix
Row with max 1s
Sorted matrix
Max rectangle
Find A Specific Pair In Matrix
Rotate A Matrix By 90 Degree In Clockwise Direction Without Using Any Extra Space
Kth smallest element in a Matrix
Common Elements In All Rows Of A Given Matrix
Reverse String
Count and Say
Longest Common Prefix
Palindrome String
Print All The Duplicates In The Input String
A Program To Check If Strings Are Rotations Of Each Other
Longest Palindrome in a String
Longest Repeating Subsequence
Print Subsequences String
Permutations of a String
Split the binary string into substrings with equal number of 0s and 1s
Word Wrap
Edit Distance
Next Permutation
Parenthesis Checker
Word Break
Rabin Karp Algorithm For Pattern Searching
Longest Prefix Suffix
Convert Sentence Equivalent Mobile Numeric Keypad Sequence
Count the Reversals
Count Palindromic Subsequences
Find Count Number Given String Present 2d Character Array
Find the string in grid
Boyer Moore Algorithm For Pattern Searching
Roman Number to Integer
Min Number of Flips
Second most repeated string in a sequence
Minimum Swaps for Bracket Balancing
Longest Common Subsequence
Program Generate Possible Valid Ip Addresses Given String
Smallest distinct window
Rearrange characters
Minimum Characters Added Front Make String Palindrome
Print Anagrams Together
Smallest window containing all characters
Remove Consecutive Characters
Wildcard string matching
Function To Find Number Of Customers Who Could Not Get A Computer
Transform One String To Another Using Minimum Number Of Given Operation
Isomorphic Strings
Recursively print all sentences that can be formed from list of word lists
Search in Rotated Sorted Array
First and Last Occurrences
Value equal to index value
Count Squares
Middle of Three
Optimum Location Point Minimize Total Distance
Missing And Repeating
Majority Element
Searching Array Adjacent Differ K
Find Pair Given Difference
4 Sum - All Quadruples
Stickler Thief
Triplets with Smaller Sum
Rearrange characters
Zero Sum Subarrays
Product array puzzle
Sort by Set Bit Count
Minimum Swaps to Sort
rasta and kheshtak
kth smallest number again 2
K-th element of two Arrays
AGGRCOW
Allocate Minimum Pages
EKO
Weighted Job Scheduling Log N Time
Arithmetic Number
Smallest number with at least n trailing zeroes in factorial
PRATA
ANARC05B
Count Inversions
In Place Merge Sort
Middle of the Linked List
Reverse a linked list
Linked List Group Reverse
Detect Loop in linked list
Remove loop in Linked List
Find First Node Of Loop In A Linked List
Remove Duplicates from a Sorted Linked List
Remove duplicates from an unsorted linked list
Move Last Element To Front Of A Given Linked List
Add 1 to a Linked List Number
Add Number Linked Lists
Intersection Sorted Linked Lists
Intersection in Y Shaped Lists
Merge Sort for Linked List
Quick Sort on Linked List
Check If Circular Linked List
Split a Linked List into two halves
Palindrome Linked List
Deletion Circular Linked List
Reverse a Doubly Linked List
Find Pairs Given Sum Doubly Linked List
Count Triplets Sorted Doubly Linked List Whose Sum Equal Given Value X
Sort K Sorted Doubly Linked List
Rotate Doubly Linked List N Nodes
Reverse Doubly Linked List Groups Given Size
Flattening a Linked List
Sort a linked list of 0s, 1s and 2s
Clone List with Next and Random
Merge K sorted linked lists
Multiply two linked lists
Delete nodes having greater value on right
Segregate even and odd nodes in a Linked List
Kth from End of Linked List
Stream First Non-repeating
Delete Node in a BST
Binary Search Tree Set 1 Search And Insertion
Minimum element in BST
Predecessor and Successor
Check for BST
Populate Inorder Successor for all nodes
Lowest Common Ancestor in a BST
Construct Bst From Given Preorder Traversa
Binary Tree to BST
Convert Normal Bst Balanced Bst
Merge Two Balanced Binary Search Trees
Kth largest element in BST
k-th Smallest in BST
Find Sum Pairs Across Two BSTs
Find Median Bst Time O1 Space
Count BST nodes that lie in a given range
Replace every element with the least greater element on its right
Given N Appointments Find Conflicting Appointments
Preorder to BST
BST with Dead End
Largest BST
Flatten Bst To Sorted List Increasing Order
Remove Invalid Parentheses
Rat in a Maze
Printing Solutions N Queen Problem
Word Break - 2
Solve the Sudoku
M-Coloring Problem
Given A String Print All Possible Palindromic Partition
Partition Equal Subset Sum
The Knights Tour Problem Backtracking 1
Tug Of War
Find Shortest Safe Route In A Path With Landmines
Target Sum Combinations
Largest number in K swaps
Permutations of a String
Find If There Is A Path Of More Than K Length From A Source
Longest Possible Route in a Matrix with Hurdles
Print All Possible Paths From Top Left To Bottom Right Of A Mxn Matrix
Partition array to k subsets
Find The K Th Permutation Sequence Of First N Natural Numbers
Reorganize String
Building Heap From Array
Heap Sort
Sliding Window Maximum Maximum Of All Subarrays Of Size K
k largest elements
Kth Smallestlargest Element Unsorted Array
Merge k Sorted Arrays
Merge two binary Max heaps
K-th Largest Sum Contiguous Subarray
Merge K sorted linked lists
Smallest range in K lists
Find median in a stream
Is Binary Tree Heap
Minimum Cost of ropes
Convert Bst Min Heap
Convert Min Heap To Max Heap
Rearrange characters
Minimum sum
Flood Fill
Clone Graph
Number of Operations to Make Network Connected
Word Ladder
Snakes and Ladders
Cheapest Flights Within K Stops
BFS of graph
Depth First Search Or Dfs For A Graph
Detect Cycle In A Graph
Undirected Graph Cycle
Rat in a Maze
Steps by Knight
Dijkstras Shortest Path Algorithm Greedy Algo 7
Topological Sort
Minimum time taken by each job to be completed given by a Directed Acyclic Graph
Find Whether It Is Possible To Finish All Tasks Or Not From Given Dependencies
Find the number of islands
Alien Dictionary
Kruskals Minimum Spanning Tree Algorithm Greedy Algo 2
Prims Minimum Spanning Tree Mst Greedy Algo 5
Total Number Spanning Trees Graph
Negative weight cycle
Floyd Warshall
Travelling Salesman Problem Set 1
Graph Coloring Applications
Bridge In A Graph
Strongly Connected
Bipartite Graph
Detect Negative Cycle Graph Bellman Ford
Find Longest Path Directed Acyclic Graph
journey to the moon
oliver and the game 3
Water Jug Problem Using Bfs
Find If There Is A Path Of More Than K Length From A Source
M-Coloring Problem
Minimum Edges Reverse Make Path Source Destination
Paths Travel Nodes Using Edgeseven Bridges Konigsberg
Vertex Cover Problem Set 1 Introduction Approximate Algorithm 2
Chinese Postman Route Inspection Set 1 Introduction
Number Of Triangles In Directed And Undirected Graphs
Minimize Cash Flow Among Given Set Friends Borrowed Money
Two Clique Problem Check Graph Can Divided Two Cliques
Longest Palindromic Substring
Maximum Length of Pair Chain
Coin Change (Count Ways)
0 - 1 Knapsack Problem
nCr
Permutation Coefficient
Program Nth Catalan Number
Matrix Chain Multiplication Dp 8
Edit Distance
Partition Equal Subset Sum
Friends Pairing Problem
Gold Mine Problem
Assembly Line Scheduling Dp 34
Painting the Fence
Maximize The Cut Segments
Longest Common Subsequence
Longest Repeating Subsequence
Longest Increasing Subsequence
Space Optimized Solution Lcs
LCS of three strings
Max Sum Increasing Subsequence
Count Subsequences Product Less K
Longest subsequence-1
Maximum Subsequence Sum Such That No Three Are Consecutive
Egg Dropping Puzzle
Sum Except First and Last
Largest square formed in a matrix
Pairs with certain difference
Maximum path sum in matrix
Maximum difference of zeros and ones in binary string
Minimum Jumps
Minimum cost to fill given weight in a bag
Minimum Removals Array Make Max Min K
Longest Common Substring
Reach a given score
BBT counter
Kadane's Algorithm
Smallest sum contiguous subarray
Knapsack with Duplicate Items
Word Break
Largest Independent Set Problem Dp 26
Longest Palindromic Subsequence Dp 12
Count Palindromic Subsequences
Longest alternating subsequence
Weighted Job Scheduling
Coin Game Winner Every Player Three Choices
Count Derangements Permutation Such That No Element Appears In Its Original Position
Maximum Profit By Buying And Selling A Share At Most Twice
Optimal Strategy For A Game
Optimal Binary Search Tree Dp 24
Palindromic Partitioning
Word Wrap
Mobile numeric keypad
Boolean Parenthesization
Largest Rectangular Sub Matrix Whose Sum 0
Largest Area Rectangular Sub Matrix Equal Number 1s 0s
Maximum sum Rectangle
Stock Buy and Sell – Max K Transactions Allowed
Interleaved Strings
Level order traversal
Reverse Level Order Traversal
Height of Binary Tree
Diameter of a Binary Tree
Create A Mirror Tree From The Given Binary Tree
Left View of Binary Tree
Right View of Binary Tree
Top View of Binary Tree
Bottom View of Binary Tree
ZigZag Tree Traversal
Balanced Tree Check
Diagonal Tree Traversal
Tree Boundary Traversal
Construct Binary Tree String Bracket Representation
Binary Tree to DLL
Transform to Sum Tree
Construct Tree from Inorder & Preorder
Minimum Swap Required Convert Binary Tree Binary Search Tree
Sum Tree
Leaves at Same Level or Not
Duplicate Subtree
Check Mirror in N-ary tree
Sum of nodes on the longest path
Check Given Graph Tree
Find Largest Subtree Sum Tree
Maximum Sum Nodes Binary Tree No Two Adjacent
Print K Sum Paths Binary Tree
LCA in Binary Tree
Min distance between two given nodes of a Binary Tree
Kth Ancestor Node Binary Tree Set 2
Duplicate Subtrees
Isomorphic Trees
N meetings in one room
Job Sequencing Problem
Huffman Encoding
Water Connection Problem
Fractional Knapsack
Choose and Swap
Maximum Trains Stoppage Can Provided
Minimum Platforms
Buy Maximum Stocks Stocks Can Bought Th Day
Shop in Candy Store
Minimize Cash Flow Among Given Set Friends Borrowed Money
Minimum Cost Cut Board Squares
Survival
Find Maximum Meetings In One Room
Maximum Product Subset Array
Maximize sum after K negations
Max Value Permutation
Maximum Sum Absolute Difference Array
Swap and Maximize
Minimum Sum Absolute Difference Pairs Two Arrays
Program For Shortest Job First Or Sjf Cpu Scheduling Set 1 Non Preemptive
Page Faults in LRU
Smallest Subset Sum Greater Elements
Chocolate Distribution Problem
DEFKIN
DIEHARD
GERGOVIA
GCJ101BB
CHOCOLA
ARRANGE
K Centers Problem Set 1 Greedy Approximate Algorithm
Minimum Cost of ropes
Smallest number
Rearrange characters
Find Maximum Sum Possible Equal Sum Three Stacks
Queue Set 1introduction And Array Implementation
Two Stacks in an Array
Design A Stack With Find Middle Operation
Efficiently Implement K Stacks Single Array
Parenthesis Checker
Reverse Using Stack
Special Stack
Next Greater Element
The Celebrity Problem
Arithmetic Expression Evalution
Postfix Evaluation
Reverse A Stack Using Recursion
Sort a stack
Overlapping Intervals
Histogram Max Rectangular Area
Valid Substring
Expression Contains Redundant Bracket Not
Stack using Queue
Implement Stack Queue Using Deque
Stack Permutations Check If An Array Is Stack Permutation Of Other
Queue using two Stacks
Efficiently Implement K Queues Single Array
Circular Queue Set 1 Introduction Array Implementation
LRU Cache
Queue Reversal
Reverse first K of a Queue
Interleave First Half Queue Second Half
Gas Station
Rotten Oranges
Distance of nearest cell having 1
First negative in every window of size k
Check if all levels of two trees are anagrams or not
Sum Minimum Maximum Elements Subarrays Size K
Game with String
Stream First Non-repeating
Next Smaller Element
Trie Insert And Search
Find All Shortest Unique Prefixes To Represent Each Word In A Given List
Word Break Problem Trie Solution
Print Anagrams Together
Phone directory
Unique rows in boolean matrix
Number of 1 Bits
Unique Number II
Bit Difference
Count set bits
Power of 2
Find position of set bit
Copy Set Bits In A Range
Divide Two Integers Without Using Multiplication Division Mod Operator
Calculate Square Of A Number Without Using And Pow
Power Set
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Frequently asked questions
What is the Love Babbar DSA Sheet?
A well-structured roadmap covering every major data structures and algorithms concept needed for placement interviews, created by Love Babbar.
How many problems does it have?
430 problems across 15 topic sections, from arrays and matrices through advanced trees and dynamic programming.
Is it free to use?
Yes. Browsing every problem on this page is completely free, with no account required. Creating a free DevsUnite account lets you save your checked-off progress, star favorites, and add personal notes that sync across devices.
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You can read and solve every problem without logging in. An account is only required to mark a problem as done, star it, or add a note. Those actions save to your account instead of resetting on refresh.