hackerrank-solutions

Solutions to the problems on Hackerrank.

Algorithms

DataStructures

Mathematics

Fundamentals
Number Theory
Combinatorics
Algebra
Geometry
Probability
Linear Algebra Foundations

Java

Introduction
Strings
BigNumber
Data Structures
Object Oriented Programming
Exception Handling
Advanced

Warmup

Title	Solution	Time	Space	Difficulty	Points
Solve Me First	Java	O(1)	O(1)	Easy	1
Simple Array Sum	Java	O(n)	O(1)	Easy	10
Compare the Triplets	Java	O(1)	O(1)	Easy	10
A Very Big Sum	Java	O(n)	O(1)	Easy	10
Diagonal Difference	Java	O(n)	O(1)	Easy	10
Plus Minus	Java	O(n)	O(1)	Easy	10
Staircase	Java	O(n)	O(n)	Easy	10
Mini-Max Sum	Java	O(1)	O(1)	Easy	10
Time Conversion	Java	O(1)	O(1)	Easy	15
Birthday Cake Candles	Java	O(n)	O(1)	Easy	10

Implementation

Title	Solution	Time	Space	Difficulty	Points	Note
Grading Students	Java	O(n)	O(1)	Easy	10
Apple and Orange	Java	O(n+m)	O(1)	Easy	10
Kangaroo	Java	O(1)	O(1)	Easy	10
Between Two Sets	Java	O(x(n+m))	O(1)	Easy	10	x=(max(m) - min(n))/min(n)
Divisible Sum Pairs	Java	O(n^2)	O(1)	Easy	10
Birthday Chocolate	Java	O(n)	O(1)	Easy	10
Breaking the Records	Java	O(n)	O(1)	Easy	10
Migratory Birds	Java	O(n)	O(1)	Easy	10
Day of the Programmer	Java	O(1)	O(1)	Easy	15
Bon Appetit	Java	O(n)	O(1)	Easy	10
Sock Merchant	Java	O(n)	O(n)	Easy	10
Drawing Book	Java	O(1)	O(1)	Easy	10
Counting Valleys	Java	O(n)	O(1)	Easy	15
Cats and a Mouse	Java	O(1)	O(1)	Easy	15
Electronics Shop	Java	O(n log (n))	O(1)	Easy	15	n = m+n
Picking Numbers	Java	O(n)	O(n)	Easy	20
Climbing the Leaderboard	Java	O(n+m)	(n)	Easy	20
The Hurdle Race	Java	O(n)	O(1)	Easy	15
Designer PDF Viewer	Java	O(n)	O(n)	Easy	20
Forming a Magic Square	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Forming a Magic Square/Solution.java)	O(1)	O(1)	Easy	20
Utopian Tree	Java	O(n)	O(1)	Easy	20
Angry Professor	Java	O(n)	O(1)	Easy	20
Beautiful Days at the Movies	Java	O(n)	O(1)	Easy	15
Viral Advertising	Java	O(n)	O(1)	Easy	15
Save the Prisoner!	Java	O(1)	O(1)	Easy	15
Circular Array Rotation	Java	O(n)	O(1)	Easy	20
Sequence Equation	Java	O(n)	O(n)	Easy	20
Jumping on the Clouds: Revisited	Java	O(n)	O(n)	Easy	15
Find Digits	Java	O(n)	O(1)	Easy	25
Extra Long Factorials	Java	O(n)	O(1)	Medium	20
Append and Delete	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Append and Delete/Solution.java)	O(n)	O(1)	Easy	20
Sherlock and Squares	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Sherlock and Squares/Solution.java)	O(n)	O(1)	Easy	20
Library Fine	Java	O(1)	O(1)	Easy	15
Cut the sticks	Java	O(n log(n))	O(n)	Easy	25
Non-Divisible Subset	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Non-Divisible Subset/Solution.java)	O(n)	O(n)	Medium	20
Repeated String	Java	O(n)	O(n)	Easy	20
Jumping on the Clouds	Java	O(n)	O(n)	Easy	20
Equalize the Array	Java	O(n)	O(n)	Easy	20
Queen's Attack II	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Queen's Attack II/Solution.java)	O(k)	O(1)	Medium	30
ACM ICPC Team	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/ACM ICPC Team/Solution.java)	O(n^3)	O(n)	Easy	25
Taum and B'day	Java	O(1)	O(1)	Easy	25
Organizing Containers of Balls	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Organizing Containers of Balls/Solution.java)	O(n^2)	O(n^2)	Medium	30
Encryption	Java	O(n)	O(1)	Medium	30
Bigger is Greater	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Bigger is Greater/Solution.java)	O(n)	O(n)	Medium	35
Modified Kaprekar Numbers	Java	O(n)	O(1)	Easy	30
Minimum Distances	Java	O(n)	O(n)	Easy	20
Beautiful Triplets	Java	O(n)	O(n)	Easy	20
Strings: Making Anagrams	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Strings Making Anagrams/Solution.java)	O(\|a\|+\|b\|)	O(1)	Easy	30
The Time in Words	Java	O(1)	O(1)	Medium	25
Chocolate Feast	Java	O(log(n))	O(1)	Easy	25	Base of logarithmic time complexity is m
Service Lane	Java	O(n)	O(n)	Easy	20
Lisa's Workbook	Java	O(n)	O(1)	Easy	25
Flatland Space Stations	Java	O(n)	O(n)	Easy	25
Fair Rations	Java	O(n)	O(1)	Easy	25
Cavity Map	Java	O(n^2)	O(n^2)	Easy	30
Manasa and Stones	Java	O(n)	O(1)	Easy	30
The Grid Search	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/The Grid Search/Solution.java)	O(n)	O(n)	Medium	30	n = len(word)
Happy Ladybugs	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Happy Ladybugs/Solution.java)	O(n)	O(n)	Easy	30
Strange Counter	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Strange Counter/Solution.java)	O(n)	O(1)	Easy	30	n = t
Absolute Permuation	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Absolute Permuation/Solution.java)	O(n)	O(n)	Medium	40
The Bomberman Game	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/The Bomberman Game/Solution.java)	O(nm)*	O(nm)*	Medium	40
Ema's Supercomputer	Java			Medium	40
Larry's Array	Java			Medium	40
Almost Sorted	Java			Medium	50
Matrix Layer Rotation		O(nm)*	O(nm)*	Hard	80
Consecutive 1s in Binary Numbers	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Consecutive 1s in Binary Numbers/Solution.java)	O(n)	O(1)	Easy	30
Nested Logic	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Nested Logic/Solution.java)	O(1)	O(1)	Easy	40
Bitwise AND	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Implementation/Bitwise AND/Solution.java)	O(1)	O(1)	Easy	20

Strings

Title	Solution	Time	Space	Difficulty	Points	Note
Super Reduced String	Java	O(n)	O(n)	Easy	10
camelCase	Java	O(n)	O(1)	Easy	15
Strong Password		O(n)	O(1)	Easy	15
Two Characters	Java	O(n)	O(n)	Easy	15
Caesar Cipher	Java	O(n)	O(n)	Easy	15
Caesar Cipher: Encryption	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Caesar Cipher Encryption/Solution.java)	O(n)	O(n)	Easy	40
Mars Exploration	Java	O(n)	O(1)	Easy	15
HackerRank in a String!	Java	O(n)	O(1)	Easy	20
Pangrams	Java	O(n)	O(1)	Easy	20
Weighted Uniform Strings	Java	O(n)	O(n)	Easy	20
Separate the Numbers	Java	O(n)	O(n)	Easy	20
Funny String	Java	O(n)	O(n)	Easy	25
Gemstones	Java	O(n)	O(1)	Easy	20
Alternating Characters	Java	O(n)	O(1)	Easy	20
Beautiful Binary String	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Beautiful Binary String/Solution.java)	O(n)	O(1)	Easy	20
The Love-Letter Mystery	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/The Love-Letter Mystery/Solution.java)	O(n)	O(1)	Easy	20
Determining DNA Health	Java			Hard	50
Palindrome Index	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Palindrome Index/Solution.java)	O(n)	O(1)	Easy	25
Anagram	Java	O(n)	O(1)	Easy	25
Making Anagrams	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Making Anagrams/Solution.java)	O(n)	O(n)	Easy	30
Game of Thrones - I	Java	O(n)	O(1)	Easy	30
Two Strings	Java	O(\|a\| + \|b\|)	O(1)	Easy	25	a and b are lengths of the input strings
String Construction	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/String Construction/Solution.java)	O(n)	O(n)	Easy	25
Sherlock and Valid String	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Sherlock and Valid String/Solution.java)	O(n)	O(n)	Hard	100
Richie Rich	Java	O(n)	O(n)	Medium	30
Sherlock and Anagrams	Java			Medium	50
Common Child	Java			Hard	60
Bear and Steady Gene	Java			Medium	50
Morgan and a String	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Strings/Morgan and a String/Solution.java)	O((\|a\|+\|b\|)^2)	O(\|a\| + \|b\|)	Expert	100
Count Strings	Java			Hard	80
String Function Calculation	Java			Advanced	80
Build a Palindrome	Java			Advanced	80
Build a String	Java			Hard	80
Gridland Provinces	Java			Hard	80
Ashton and String	Java			Advanced	100
String Similarity	Java			Expert	100
Super Functional Strings	Java			Advanced	80
Circular Palindromes	Java			Advanced	120
Similar Strings	Java			Advanced	85
Save Humanity	Java			Expert	100
Find Strings	Java			Expert	100
Palindromic Border	Java			Expert	100
Two Two	Java			Advanced	150
Two Strings Game	Java			Expert	100
Letter Islands	Java			Expert	100
Pseudo-Isomorphic Substrings	Java			Expert	100
How Many Substrings?	Java			Expert	100

Sorting

Title	Solution	Time	Space	Difficulty	Points	Note
Intro to Tutorial Challenges	Java	O(n)	O(1)	Easy	30
Insertion Sort - Part 1	Java	O(n)	O(1)	Easy	30
Insertion Sort - Part 2	Java	O(n^2)	O(1)	Easy	30
Correctness and the Loop Invariant	Java	O(n^2)	O(1)	Easy	30
Running Time of Algorithms	Java	O(n^2)	O(1)	Easy	30
Quicksort 1 - Partition	Java	O(n)	O(n)	Easy	10
Quicksort 2 - Sorting	Java	O(n^2)	O(n)	Easy	30
Quicksort In-Place	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Sorting/Quicksort In-Place/Solution.java)	O(n^2)	O(log(n))	Medium	35
Running Time of Quicksort	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Sorting/Running Time of Quicksort/Solution.java)	O(n log(n))	O(log(n))	Easy	35
Counting Sort 1	Java	O(n+k)	O(k)	Easy	30	value of k in this problem is 100
Counting Sort 2	Java	O(n+k)	O(n+k)	Easy	30	Value of k is 100 in this problem.
Counting Sort 3	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Sorting/Counting Sort 3/Solution.java)	O(n+k)	O(k)	Easy	30
The Full Counting Sort	Java	O(n+k)	O(n+k)	Medium	40
Closest Numbers	Java	O(n log(n))	O(n)	Easy	35
Find the Median	Java	O(n log(n))	O(n)	Easy	35
Insertion Sort Advanced Analysis	Java			Advanced	50
Fraudulent Activity Notifications	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Sorting/Fraudulent Activity Notifications/Solution.java)	O(n^2)	O(n)	Medium	40
Lily's Homework	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Sorting/Lily's Homework/Solution.java)	O(n log(n))	O(n)	Medium	40
Big Sorting	Java	O(n log(n))	O(n)	Easy	20

Search

Title	Solution	Time	Space	Difficulty	Points	Note
Hackerland Radio Transmitters	JS	O(n log(n))	O(n)	Medium	25
Ice Cream Parlor	Java	O(n)	O(n)	Easy	30
Binary Search: Ice Cream Parlor	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Search/Binary Search Ice Cream Parlor/Solution.java)	O(n)	O(n)	Easy	35
Gridland Metro	Java	O(k)	O(k)	Medium	25	k = number of tracks
Missing Numbers	Java[	O(n)	O(n)	Easy	45
Minimum Loss	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Search/Minimum Loss/Solution.java)	O(n log(n))	O(n)	Medium	35
KnightL on a Chessboard	Java			Medium	35
Pairs	Java[	O(n log(n))	O(n)	Medium	50
Sherlock and Array	Java[	O(n)	O(n)	Easy	40
Maximum Subarray Sum	Java			Hard	65
Connected Cells in a grid	Java			Medium	50
Short Palindrome	Java			Medium	40
Maximizing Mission Points	Java			Hard	70
Count Luck	Java			Medium	50
Cut the Tree	Java			Medium	50
Making Candies	Java			Hard	45
Gena Playing Hanoi	Java			Medium	50
Beautiful Quadruples	Java			Medium	50
Bike Racers	Java			Hard	65
Task Scheduling	Java			Advanced	70
Similar Pair	Java			Advanced	70
Absolute Element Sums	Java			Hard	70
Sorted Subsegments	Java			Hard	80
Distant Pairs	Java			Expert	80
King Richard's Knights	Java			Hard	80

Graph Theory

Title	Solution	Time	Space	Difficulty	Points
Roads and Libraries	Java			Medium	30
Synchronous Shopping	Java			Medium	40
Crab Graphs	Java			Medium	50
Even Tree	Java			Medium	50
Snakes and Ladders: The Quickest Way Up	Java			Medium	50
Subset Component	Java			Hard	50
Journey to the Moon	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Graph Theory/Journey to the Moon/Solution.java)	O(n + i)	O(n)	Medium	50
Kruskal (MST): Really Special Subtree	Java			Hard	50
Minimum Penalty Path	Java			Medium	50
Demanding Money	Java			Hard	50
The Story of a Tree	Java			Medium	50
Breadth First Search: Shortest Reach	Java			Medium	55
The Value of Friendship	Java			Hard	55
Clique	Java			Medium	60
Dijkstra: Shortest Reach 2	Java			Hard	60
Prim's (MST) : Special Subtree	Java			Medium	60
Roads in Hackerland	Java			Medium	60
Toll Cost Digits	Java			Hard	60
Real Estate Broker	Java			Hard	60
Matrix	Java			Hard	70
Bead Ornaments	Java			Advanced	70
Rust & Murderer	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Graph Theory/Rust & Murderer/Solution.java)	O(n+m)	O(n)	Medium	70
Recording Episodes	Java			Hard	70
Kingdom Connectivity	Java			Hard	75
Journey Scheduling	Java			Hard	75
Floyd : City of Blinding Lights	Java			Hard	75
Find the Path	Java			Hard	75
Repair Roads	Java			Hard	80
Problem solving	Java			Hard	80
Computer Game	Java			Hard	80
Jack goes to Rapture	Java			Medium	80
Jim and his LAN Party	Java			Hard	80
Jeanie's Route	Java			Medium	80
Travel in HackerLand	Java			Hard	80
Jogging Cats	Java			Advanced	80
Tree Flow	Java			Hard	80
Tripartite Matching	Java			Hard	80
Jumping Rooks	Java			Advanced	80
Minimum MST Graph	Java			Expert	80
Coprime Paths	Java			Expert	80
DAG Queries	Java			Expert	80
Liars	Java			Advanced	85
ByteLandianTours	Java			Hard	90
Kth Ancestor	Java			Hard	90
Drive	Java			Expert	90
Road Network	Java			Expert	90
Savita And Friends	Java			Hard	90
Favorite sequence	Java			Advanced	95
Quadrant Queries	Java			Advanced	100
Going to the Office	Java			Expert	100
Ticket	Java			Expert	100
HackerX	Java			Hard	100
Hacker Country	Java			Hard	100
Travelling Salesman in a Grid	Java			Expert	100
Huarongdao	Java			Expert	100
Vertical Paths	Java			Expert	100
DFS Edges	Java			Expert	100
Tree Splitting	Java			Advanced	100
Definite Random Walks	Java			Expert	100
Diameter Minimization	Java			Expert	100
Training the army	Java			Hard	120
Alex vs Fedor	Java			Expert	150

Greedy

Title	Solution	Time	Space	Difficulty	Points
Minimum Absolute Difference in an Array	Java	O(n log(n))	O(n)	Easy	15
Chief Hopper	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Chief Hopper/Solution.java)	O(n)	O(n)	Hard	65
Mark and Toys	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Mark and Toys/Solution.java)	O(n log(n))	O(n)	Easy	35
Marc's Cakewalk	Java	O(n + k)	O(k)	Easy	15
Grid Challenge	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Grid Challenge/Solution.java)	O(n(n log (n)))*	O(n^2)	Easy	20
Luck Balance	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Luck Balance/Solution.java)	O(n log(n))	O(1)	Easy	20
Maximum Perimeter Triangle	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Maximum Perimeter Triangle/Solution.java)	O(n log (n))	O(n)	Easy	20
Permuting Two Arrays	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Permuting Two Arrays/Solution.java)	O(n log (n))	O(n)	Easy	40
Jim and the Orders	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Jim and the Orders/Solution.java)	O(n log (n))	O(n)	Easy	40
Equal Stacks	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Equal Stacks/Solution.java)	O(n)	O(n)	Easy	25
Sherlock and The Beast	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Sherlock and The Beast/Solution.java)	O(n)	O(n)	Easy	30
Priyanka and Toys	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Priyanka and Toys/Solution.java)	O(n log(n))	O(n)	Easy	30
Largest Permutation		O(n)	O(n)	Easy	30
Beautiful Pairs	Java			Easy	30
Yet Another Minimax Problem	Java			Medium	20
Flipping the Matrix	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Constructve Algorithms/Flipping Matrix/Solution.java)	O(n^2)	O(n^2)	Medium	30
Roads and Libraries	Java			Medium	30
Greedy Florist		O(n log (n))	O(n)	Medium	35
Mark and Toys	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Mark and Toys/Solution.java)	O(n log(n))	O(n)	Easy	35
Max Min	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Max Min/Solution.java)	O(n log(n))	O(1)	Medium	35
Permuting Two Arrays	Java			Easy	40
Jim and the Orders	Java			Easy	40
Goodland Electricity	Java			Medium	40
Fun Game	Java			Medium	40
Reverse Shuffle Merge	Java			Advanced	50
Cutting Boards	Java			Hard	60
Algorithmic Crush	Java			Hard	60
Prim's (MST): Special Subtree	Java			Medium	60
Accessory Collection	Java			Hard	60
Chief Hopper	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Greedy/Chief Hopper/Solution.java)	O(n)	O(n)	Hard	65
Sherlock and MiniMax	Java			Hard	70
Team Formation	Java			Advanced	70

Dynamic Programming

Title	Solution	Time	Space	Difficulty	Points
Equal	Java			Medium	30
Cut Tree	Java			Medium	40
Mr K marsh	Java			Medium	40
Sam and sub-strings	Java			Medium	40
Summing Pieces	Java			Medium	40
Short Palindrome	Java			Medium	40
Abbreviation	Java			Medium	40
Fair Cut	Java			Medium	40
Fibonacci Modified	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Dynamic Programming/Modified Fibonacci/Solution.java)			Medium	45
Lego Blocks	Java			Medium	50
Candies	Java			Medium	50
Stock Maximize	Java			Medium	50
Angry Childtren 2	Java			Hard	50
The Maximum Subarray	Java			Medium	50
Sherlock and Cost	Java			Medium	50
Xor and Sum	Java			Medium	50
Counting Special Sub-Cubes	Java			Medium	50
Two Robots	Java			Medium	50
Kingdom Division	Java			Medium	50
Prime XOR	Java			Medium	50
HackerRank City	Java			Medium	50
Nikita and the Game	Java			Medium	50
Prime Digit Sums	Java			Medium	50
Mandragora Forest	Java			Medium	50
LCS Returns	Java			Medium	50
Grid Walking	Java			Medium	55
Bricks Game	Java			Medium	55
The Longest Common Subsequence	Java			Medium	55
Substring Diff	Java			Medium	60
Brick Tiling	Java			Hard	60
Alien Languages	Java			Hard	60
The Longest Increasing Subsequence	Java			Advanced	60
The Coin Change Problem		O(NM)*	O(N)	Hard	60
Knapsack	Java			Medium	60
Sherlock's Array Merging Algorithm	Java			Hard	60
New Year Game	Java			Medium	60
Shashank and the Palindromic Strings	Java			Advanced	60
Decibinary Numbers	Java			Hard	60
Choosing White Balls	Java			Hard	60
DP: Coin Change	Java			Hard	60
Clues on a Binary Path	Java			Hard	60
GCD Matrix	Java			Hard	60
Coin on the Table	Java			Medium	65
Interval Selection	Java			Medium	65
Red John is Back	Java			Medium	65
Play with words	Java			Medium	65
Queens on Board	Java			Hard	70
String Reduction	Java			Hard	70
Far Vertices	Java			Hard	70
The Indian Job	Java			Medium	70
Hexagonal Grid	Java			Hard	70
Longest Palindromic Subsequence	Java			Hard	70
Turn Off the Lights	Java			Hard	70
Tara's Beautiful Permutations	Java			Hard	70
Two Subarrays	Java			Expert	70
Mining	Java			Advanced	75
The Longest Common Subsequence (LCS)	Java			Hard	75
Points in a Plane	Java			Advanced	80
Fairy Chess	Java			Advanced	80
Billboards	Java			Advanced	80
Requirement	Java			Advanced	80
A Super Hero	Java			Hard	80
Covering the stains	Java			Hard	80
Superman Celebrates Diwali	Java			Hard	80
Wet Shark and Two Subsequences	Java			Medium	80
Zurikela's Graph	Java			Hard	80
New Year Present	Java			Hard	80
Suffix Rotation	Java			Expert	80
Black and White Tree	Java			Hard	80
Beautiful Strings	Java			Hard	80
Longest Mod Path	Java			Hard	80
Super Functional Strings	Java			Advanced	80
Kitty's Calculations on a Tree	Java			Advanced	80
Liars	Java			Advanced	85
Dorsey Thief	Java			Advanced	85
Swap Permutation	Java			Medium	85
Candles Counting	Java			Medium	85
Square Subsequences	Java			Hard	90
Hyper Strings	Java			Advanced	90
Unique Divide And Conquer	Java			Advanced	90
Super Kth LIS	Java			Advanced	90
Counting Road Networks	Java			Expert	90
Lucky Numbers	Java			Expert	100
Count Scorecards	Java			Expert	100
Unfair Game	Java			Advanced	100
Oil Well	Java			Hard	100
Modify The Sequence	Java			Advanced	100
Divisible Numbers	Java			Expert	100
Ones and Twos	Java			Hard	100
Extremum Permutations	Java			Medium	100
Tree Pruning	Java			Advanced	100
P-sequences	Java			Hard	100
Best spot	Java			Advanced	100
Find the Seed	Java			Advanced	100
The Blacklist	Java			Advanced	100
Police Operation	Java			Hard	100
Road Maintenance	Java			Hard	100
King and Four Sons	Java			Expert	100
Counting the Ways	Java			Expert	100
Hard Disk Drives	Java			Expert	100
Travel around the world	Java			Medium	120
Robot	Java			Advanced	120
Vim War	Java			Advanced	120
Dortmund Dilemma	Java			Advanced	150
Separate the chocolate	Java			Expert	250

Constructive Algorithms

Title	Solution	Time	Space	Difficulty	Points
Lena Sort	Java			Medium	30
Flipping the Matrix	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Constructve Algorithms/Flipping Matrix/Solution.java)	O(n^2)	O(n^2)	Medium	30
Gaming Array	Java			Medium	35
New Year Chaos	Java			Medium	40
Bonetrousle	Java			Medium	50
Yet Another KMP Problem	Java			Hard	60
Beautiful 3 Set	Java			Hard	60
Inverse RMQ	Java			Hard	60
Two Subarrays	Java			Expert	70
Lovely Triplets	Java			Advanced	80
Array Construction	Java			Advanced	80

Bit Manipulation

Title	Solution	Time	Space	Difficulty	Points
Lonely Integer	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Bit Manipulation/Lonely Integer/Solution.java)	O(n)	O(1)	Easy	20
Maximizing XOR	Java			Easy	30
Counter game	Java			Medium	30
Xor-sequence	Java			Medium	40
Sum vs XOR	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Algorithms/Bit Manipulation/Sum vs XOR/Solution.java)	O(n log(n))	O(1)	Easy	20
The Great XOR	Java			Medium	25
Flipping bits	Java			Easy	40
Yet Another Minimax Problem	Java			Medium	30
Sansa and XOR	Java			Medium	30
AND Product	Java			Medium	40
Xoring Ninja	Java			Hard	55
Cipher	Java			Medium	50
XOR Matrix	Java			Hard	50
What's Next?	Java			Medium	50
String Transmission	Java			Hard	60
A or B	Java			Medium	50
Manipulative Numbers	Java			Hard	55
Stone game	Java			Hard	70
2's complement	Java			Advanced	70
Changing Bits	Java			Advanced	70
XOR key	Java			Advanced	80
Maximizing the Function	Java			Hard	70
XOR Subsequences	Java			Advanced	80
Iterate It	Java			Expert	90
Hamming Distance	Java			Expert	150
Mixing proteins	Java			Hard	80

Recursion

Title	Solution	Difficulty	Points
The Power Sum	Java	Easy	20
Crossword Puzzle	Java	Medium	30
Recursive Digit Sum	Java	Medium	30
Simplified Chess Engine	Java	Medium	40
Password Cracker	Java	Medium	40
Artithmetic Expressions	Java	Hard	40
K Factorization	Java	Hard	50
Bowling Pins	Java	Advanced	60
Simplified Chess Engine II	Java	Hard	60
Repetitive K-Sums	Java	Advanced	150

Game Theory

Title	Solution	Time	Space	Difficulty	Points
Game of Stones		O(n)	O(1)	Easy	15
Tower Breakers	Java			Easy	15
A Chessboard Game	Java			Easy	15
Introduction to Nim Game	Java			Easy	15
Misère Nim	Java			Easy	20
Nimble Game	Java			Easy	20
Alice and Bob's Silly Game	Java			Medium	30
Poker Nim	Java			Easy	20
Tower Breakers, Revisited!	Java			Medium	25
Tower Breakers, Again!	Java			Medium	30
Zero-Move Nim	Java			Medium	50
Chessboard Game, Again!	Java			Medium	30
Digits Square Board	Java			Medium	35
Fun Game	Java			Medium	40
Stone Division	Java			Hard	50
Chocolate in Box	Java			Medium	70
Kitty and Katty	Java			Medium	80
Powers Game	Java			Medium	50
Deforestation	Java			Medium	50
Bob and Ben	Java			Medium	50
Tower Breakers - The Final Battle	Java			Medium	50
Simple Game	Java			Hard	60
Permutation game	Java			Medium	70
Move the Coins	Java			Hard	60
Play on benders	Java			Medium	70
New Year Game	Java			Medium	60
Stone Piles	Java			Hard	80
Chocolate Game	Java			Hard	90
Manasa and Prime game	Java			Hard	90
Vertical Rooks	Java			Medium	90
A stones game	Java			Medium	90
Tastes Like Winning	Java			Expert	100

NP Complete

Title	Solution	Difficulty	Points
Walking the Approximate Longest Path	Java	Hard	70
Sam's Puzzle (Approximate)	Java	Advanced	85
Spies, Revised	Java	Expert	100
TBS Problem	Java	Expert	100

Object Oriented Programming

Title	Solution	Time	Space	Difficulty	Points
Class vs. Instance	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Java/Class vs. Instance/Solution.java)	N/A	N/A	Easy	30
Inheritance	Java	O(n)	O(1)	Easy	30
Abstract Classes	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Java/Abstract Classes/Solution.java)	N/A	N/A	Easy	30
Complex Numbers	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/Java/Complex Numbers/Solution.java)	O(1)	O(1)	Easy	30

Arrays

Title	Solution	Time	Space	Difficulty	Points	Note
Arrays - DS	)	O(n)	O(n)	Easy	10
2D Array - DS	)	O(1)	O(1)	Easy	15
Sparse Arrays		O(n + q)	O(n + q)	Medium	25	n = number of input strings, q = number of queries
Dynamic Array		O(q)	O(n)	Easy	15	q = Number of queries

Linked Lists

Title	Solution	Time	Space	Difficulty	Points
Print the Elements of a Linked List	)	O(n)	O(1)	Easy	5
Reverse a Linked List	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/DataStructures/Linked Lists/Reverse a linked list/Solution.java)	O(n)	O(1)	Easy	5
Compare Two Linked Lists	)	O(n)	O(1)	Easy	5
Delete a node	)	O(n)	O(1)	Easy	5

Trees

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Tree: Preorder Traversal	)	O(n)	O(n)	Easy	10
	[Swap Nodes Algo]		O(n)	O(n)	Medium	40

Balanced Trees

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Self Balancing Tree	)	O(log(n))	O(n)	Medium	50

Stacks

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Maximum Element	)	Push-O(1), Delete - O(n), Print - O(1)	Push - O(1), Delete - O(1), Print - O(1)	Easy	20
	Balanced Brackets	[Java](https://github.com/kinshuk4/hackerrank-solutions/blob/master/DataStructures/Stacks/Balanced Brackets/Solution.java)	O(n)	O(n)	Medium	25

Queues

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Queue using Two Stacks		Enqueue - O(1), Dequeue - O(n), Print - O(n)	Enqueue - O(1), Dequeue - O(1), Print - O(1)	Medium	30

Heap

#	Title	Solution	Time	Space	Difficulty	Points	Note
	QHEAP1		Insert - O(log(n)), Delete - O(n), Print - O(1)	Insert - O(1), Delete - O(1), Print - O(1)	Easy	25

Disjoint Set

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Spaceholder		O(1)	O(1)	Easy	1

Multiple Choice

Title	Solution	Time	Space	Difficulty	Points
Data Structures MCQ 1	[Language Independent](https://github.com/kinshuk4/hackerrank-solutions/blob/master/DataStructures/Multiple Choice/Data Structures MCQ 1/Solution.md)	NA	NA	Hard	5
Data Structures MCQ 2	[Language Independent](https://github.com/kinshuk4/hackerrank-solutions/blob/master/DataStructures/Multiple Choice/Data Structures MCQ 2/Solution.md)	NA	NA	Hard	5
Data Structures MCQ 3	[Language Independent](https://github.com/kinshuk4/hackerrank-solutions/blob/master/DataStructures/Multiple Choice/Data Structures MCQ 3/Solution.md)	NA	NA	Hard	5

Trie

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Contacts		Add - O(L), Find - O(L)	Add - O(L), Find - O(1)	Medium	40	L = Length of a contact name

Advanced

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Spaceholder		O(1)	O(1)	Easy	1

Fundamentals

#	Title	Solution	Time	Space	Difficulty	Points	Note
	Leonardo's Prime Factors		O(1)	O(1)	Easy	10

About

MIT License

Languages

Language:Java 99.8%Language:C# 0.2%