Algorithms and Data Structures in Java

The repo consists of solutions to numerous problems using different data structures and algorithms, all coded in Java. It also contains solutions to HackerRank problems which I have solved so far and questions from Cracking the Coding Interview Book (6th Edition).

You can also refer to my Java Notes for a quick refresh on the Java concepts. Lastly, feel free to connect with me on Twitter for any queries or concerns. All the best!

Contents

↥ back to Interview

1. Basic Practice:
   1. Arrays
      • ArrangeNosToFormBiggestNo
      • BooleanMatrix
      • CelebrityProblem
      • ConsecutiveElements
      • CountDivisors
      • CountSmallerElementsOnRHS
      • DistinctPairs
      • DuplicatesInArray
      • DuplicatesInArrayWithinKDistance
      • EqualProbabilityRandomNoGenerator
      • EquilibriumIndex
      • FixedPoint
      • FlattenArray
      • IntersectionAndUnionOf2SortedArrays
      • InversionsInArray
      • KLargestElements
      • KthLargestElement
      • LargestProductContiguousSubArray
      • LargestSumContiguousSubArray
      • LeadersInArray
      • LongestBitonicSubArray
      • LongestConsecutiveSubsequence
      • MajorityElement
      • MajorityElementInSortedArray
      • MatrixInSpiral
      • MaxDiffWithLargerElementAfterSmallerElement
      • MaxInAllSubArrays
      • MaxIndexDiff
      • MaxMinWithMinComparisons
      • MaxSpan
      • MaximumSizeSquareSubMatrix
      • MaximumSumNonAdjacentSubSequence
      • MedianOfStream
      • MedianOfTwoSortedArrays
      • MergeArrayOfNIntoArrayOfMPlusN
      • MinimumDistanceBetweenTwoNos
      • MissingAndRepeatingElements
      • MissingNumber
      • NextGreaterElement
      • NextLargerNumber
      • NthSmallestNumber
      • NumberOccurringOddTimes
      • OccurrencesInSortedArray
      • PairDiff
      • PairSum
      • PivotedBinarySearch
      • ProductArrayPuzzle
      • ReservoirSampling
      • ReverseArray
      • RotateArray
      • RotateMatrixBy90Degrees
      • RotatedIndex
      • SearchInSorted2DArray
      • Segregate0s1sAnd2s
      • Segregate0sAnd1s
      • SegregateEvenAndOddNos
      • SmallestAndSecondSmallest
      • SmallestMissingNumber
      • SortedSubSequence
      • SubArrayOfSum
      • SubsetOfArray
      • SymmetricDifference
      • TripletOfSum
      • TwoElementsSumClosestToZero
      • TwoRepeatingElements
      • TwoStacksInOneArray
      • UnsortedSubArray
   2. Backtracking
      • KnightTour
      • RatInAMaze
   3. Bits
      • AbsWithoutBranching
      • Addition
      • BinaryGap
      • BinaryString
      • BooleanArrayPuzzle
      • ConvertAToB
      • CountSetBits
      • CountSetBitsFromMinusNtoN
      • ElementOccurringOnce
      • FlippingBits
      • IntegerOverflow
      • LittleAndBigEndian
      • MaxWithoutBranching
      • Modulo
      • MultipleOf3
      • Multiply
      • NextHigherNumber
      • NextPowerOf2
      • OppositeSign
      • Parity
      • PowerOf2
      • PowerOf4
      • README.md
      • ReverseBits
      • RightShiftOperator
      • RightmostSetBit
      • RotateBits
      • ShiftByNegativeNumber
      • SmallestOf3Integers
      • StrCmp
      • SubBit
      • SwapBits
      • TwoNonRepeatingElements
   4. Blockchain Demo
      • Block
      • Blockchain
      • Message
      • MessageHandler
      • P2P
      • Peer
   5. Dynamic Programming
      • FibonacciNumbers
      • LongestIncreasingSubSequence
      • MaximumRectangleOf1sInMatrix
      • MinimumJumpsToReachEnd
   6. Graphs
   7. Java 8
      • DateTime
      • FlatMapInStreams
      • Lambdas
      • Streams
   8. Linked Lists
      • AddNumbersInTwoLists
      • CloneWithRandPointers
      • DeleteAlternateNodes
      • DeleteLesserNodes
      • DeleteMnodesAfterNnodes
      • DeleteNode
      • DetectAndRemoveLoop
      • DetectLoop
      • DivideCircularListIntoTwo
      • FlattenMultiLevelLinkedList
      • Identical
      • InsertInSortedCircularLinkedList
      • InsertInSortedList
      • IntersectionAndUnionOf2Lists
      • IntersectionOf2SortedLists
      • IntersectionPointOfTwoLists
      • LRUCache
      • MaximumSumLinkedList
      • MergeSort
      • MergeSortDoubleLinkedList
      • MergeTwoLinkedListAlternatively
      • MergeTwoSortedLists
      • MiddleNode
      • MoveLastNodeToFirst
      • NthNodeFromLast
      • PairWiseSwap
      • Palindrome
      • QuickSort
      • RandomNode
      • RemoveDuplicates
      • RemoveMiddlePointsFromLineSegments
      • ReverseAlternateNodesAndAppendAtEnd
      • ReverseDoubleLinkedList
      • ReverseLinkedListInAlternateGroups
      • ReverseLinkedListInGroups
      • ReverseSingleLinkedList
      • RotateLinkedList
      • SegregateEvenOddNumbers
      • SortAlternativelySortedLinkedList
      • SortLinkedListOf0s1s2s
      • SortedDLLToBBST
      • StackWithOperationOnMiddleElement
      • SwapKthNode
      • SwapNodes
      • TripletFromThreeLinkedLists
   9. Miscellaneous
      • BotTesting
      • BreakParagraph
      • CollectionIteration
      • DivideByZero
      • Equals
      • GarbageCollection
      • GenericNonGenericMix
      • HitCount
      • MapReduce
      • MapWithTimestamp
      • MethodLocalVSInner
      • MethodOverloading
      • Outer
      • OuterClassAccess
      • RandomTest
      • ReadFile
      • RecursiveWarmup
      • RegexReplaceAllSpaces
      • RegexValidateLatLong
      • ReverseAndAdd
      • TreeList
      • parenthesis
      • reverseandadd
   10. Permutations
       • StringPermutations
       • StringPermutationsCount
       • StringPermutationsWithDuplicates
       • UppercaseLowercasePermutations
   11. Searching
       • BinarySearch
       • InterpolationSearch
   12. Sorting
       • BubbleSort
       • CheckSorted
       • HeapSort
       • MergeSort
       • MergeSortSpaceOptimized
       • PancakeSort
       • QuickSort
       • SelectionSort
       • WiggleSort
   13. Stacks
       • BalancingParenthesis
       • MaxRectangleAreaInHistogram
   14. Strings
       • AnagramsTogether
       • AnagramsTogetherLexicographically
       • BasicRegexParser
       • CompressString
       • IntegerToString
       • KeepOnlyKConsecutiveLetters
       • NearPalindrome
       • RemoveDuplicatesAndArrangeLetters
       • RemoveExtraSpaces
       • StringRotation
       • StringToInteger
       • SubStringCheck
       • SubStrings
       • WithoutString
   15. Threads
       • Basics
       • NamePrint
       • ProducerConsumerUsingLockApi
       • ProducerConsumerUsingWaitNotify
       • SimpleDeadlock
   16. Trees
       • BFSUsingQueue
       • CheckForBST
       • ChildrenSum
       • ConnectNodesAtSameLevel
       • ConstructTreeFromInOrderAndPreOrder
       • DoubleTree
       • HeightBalanced
       • IdenticalTrees
       • InOrderUsingStack
       • InOrderWithoutStackAndRecursion
       • LeafNodes
       • LeastCommonAncestorInBST
       • LeastCommonAncestorInBT
       • MirrorTree
       • RandomNodeInBT
       • RootToLeafPaths
       • SecondSmallestInBST
       • SpiralTraversal
       • TreeToList
       • TwoSwappedNodesInBST
2. Cracking the Coding Interview:
   1. Arrays and Strings
      • CheckPermutation
      • IsUnique
      • OneAway
      • PalindromePermutation
      • RotateMatrix
      • StringCompression
      • StringRotation
      • URLify
      • ZeroMatrix
   2. Linked Lists
      • DeleteMiddleNode
      • Intersection
      • KthToLastElement
      • LoopDetection
      • Node
      • Palindrome
      • Partition
      • RemoveDuplicates
      • SumLists
   3. Stacks and Queues
      • QueueViaStacks
      • SortStack
      • StackMin
      • StackOfPlates
   4. Trees and Graphs
      • BuildOrder
      • CheckBalanced
      • CheckSubtree
      • FirstCommonAncestor
      • FirstCommonAncestorWithParentAccess
      • GraphNode
      • ListOfDepths
      • MinimalTree
      • RouteBetweenNodes
      • Successor
      • TreeNode
      • ValidateBST
   5. Bit Manipulation
      • BinaryToString
      • Conversion
      • Debugger
      • DrawLine
      • FlipBitToWin
      • Insertion
      • NextNumber
      • PairwiseSwap
   6. Recursion and DP
      • FibonacciNumber
3. LeetCode.
   1. arrays
      • BuySellStocks
      • BuySellStocksII
      • CanPlaceFlowers
      • FindTheCelebrity
      • InsertInterval
      • MajorityElement
      • MergeIntervals
      • MergeSortedArray
      • NumberOfIslands
      • PascalsTriangle
      • RemoveDuplicates
      • RotateArray
      • ShortestWordDistance
      • ShortestWordDistanceIII
      • SparseMatrixMultiplication
      • ValidTriangleNumber
      • binarysearch
   2. design
      • AllOne
      • DesignHitCounter
      • InsertDeleteGetRandom
      • LFUCache
      • LRUCache
   3. dynamicprogramming
      • MaximumProductSubArray
      • MaximumSubArray
      • PaintHouse
      • PaintHouseII
   4. graphs
      • GraphValidTree
      • WordLadder
      • WordLadderII
   5. hashtables
      • ContainsDuplicates
      • IsomorphicStrings
      • MyHashMap
      • MyHashSet
      • RepeatedDnaSequence
      • ShortestWordDistanceII
      • TwoSumIII
      • slidingwindow
   6. heaps
      • KthLargestElementInArray
      • TopKFrequentElements
   7. linkedlists
      • AddOneToNumberInList
      • LinkedListCycleII
      • Node
   8. math
      • BestMeetingPoint
      • ExcelSheetColumnNumber
      • ReverseInteger
   9. recursion
      • BestMeetingPoint
      • ExcelSheetColumnNumber
      • ReverseInteger
   10. stacks
       • ExclusiveTimeOfFunctions
       • ReversePolishNotation
   11. strings
       • AnagramsInString
       • CountAndSay
       • LongestCommonPrefix
       • RansomNote
       • ReverseStringII
       • ReverseVowels
       • StrStr
       • StringCompression
       • UniqueCharacterInString
       • ValidPalindrome
   12. trees
       • BinaryTreeUpsideDown
       • BinaryTreeZigZagLevelOrderTraversal
       • ClosestBinarySearchTreeValue
       • ClosestBinarySearchTreeValueII
       • LeavesOfBinaryTree
       • SecondMinNodeInBinaryTree
       • SerializeDeserializeBinaryTree
       • SymmetricTree
       • TreeNode
   13. trie
       • LongestWord
4. HackerRank.

Environment

Java Version

Java version 1.8.0_172
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)

IDE

IntelliJ IDEA 2018.1.4 (Ultimate Edition)

Machine

MacBook Pro
2.5 GHz Intel Core i7
16 GB 1600 MHz DDR3