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Merge branch 'master' into knights_tour_add_tests
2 parents f85e3e0 + 2592a08 commit d37bcf0

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‎DIRECTORY.md

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* [IndexOfRightMostSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBit.java)
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* [IsEven](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IsEven.java)
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* [IsPowerTwo](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IsPowerTwo.java)
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* [LowestSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/LowestSetBit.java)
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* [NonRepeatingNumberFinder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/NonRepeatingNumberFinder.java)
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* [NumbersDifferentSigns](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/NumbersDifferentSigns.java)
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* [ReverseBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/ReverseBits.java)
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* [AES](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AES.java)
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* [AESEncryption](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AESEncryption.java)
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* [AffineCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AffineCipher.java)
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* [Autokey](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Autokey.java)
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* [Blowfish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Blowfish.java)
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* [Caesar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Caesar.java)
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* [ColumnarTranspositionCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java)
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* [SameTreesCheck](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SameTreesCheck.java)
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* [SegmentTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SegmentTree.java)
205207
* [SplayTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SplayTree.java)
208+
* [Treap](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/Treap.java)
206209
* [TreeRandomNode](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TreeRandomNode.java)
207210
* [TrieImp](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TrieImp.java)
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* [VerticalOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversal.java)
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* [MinimizingLateness](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/MinimizingLateness.java)
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* io
280283
* [BufferedReader](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/io/BufferedReader.java)
284+
* lineclipping
285+
* [CohenSutherland](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/lineclipping/CohenSutherland.java)
286+
* [LiangBarsky](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/lineclipping/LiangBarsky.java)
287+
* utils
288+
* [Line](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/lineclipping/utils/Line.java)
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* [Point](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/lineclipping/utils/Point.java)
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* maths
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* [AbsoluteMax](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/AbsoluteMax.java)
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* [AbsoluteMin](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/AbsoluteMin.java)
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* [GenerateSubsets](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/Recursion/GenerateSubsets.java)
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* scheduling
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* [FCFSScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/FCFSScheduling.java)
469+
* [HighestResponseRatioNextScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/HighestResponseRatioNextScheduling.java)
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* [MLFQScheduler](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/MLFQScheduler.java)
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* [PreemptivePriorityScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/PreemptivePriorityScheduling.java)
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* [RRScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/RRScheduling.java)
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* [SJFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SJFScheduling.java)
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* [IndexOfRightMostSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBitTest.java)
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* [IsEvenTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IsEvenTest.java)
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* [IsPowerTwoTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IsPowerTwoTest.java)
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* [LowestSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/LowestSetBitTest.java)
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* [NonRepeatingNumberFinderTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/NonRepeatingNumberFinderTest.java)
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* [NumbersDifferentSignsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/NumbersDifferentSignsTest.java)
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* [ReverseBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/ReverseBitsTest.java)
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* [SingleBitOperationsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/SingleBitOperationsTest.java)
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* ciphers
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* a5
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* [LFSRTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/a5/LFSRTest.java)
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* [AutokeyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AutokeyTest.java)
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* [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
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* [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
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* [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java)
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* dynamicarray
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* [DynamicArrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/dynamicarray/DynamicArrayTest.java)
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* graphs
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* [BipartiteGraphDFSTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/BipartiteGraphDFSTest.java)
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* [BoruvkaAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/BoruvkaAlgorithmTest.java)
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* [DijkstraAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/DijkstraAlgorithmTest.java)
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* [EdmondsBlossomAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/EdmondsBlossomAlgorithmTest.java)
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* [PreOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/PreOrderTraversalTest.java)
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* [SameTreesCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SameTreesCheckTest.java)
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* [SplayTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SplayTreeTest.java)
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* [TreapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TreapTest.java)
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* [TreeTestUtils](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TreeTestUtils.java)
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* [TrieImpTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TrieImpTest.java)
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* [VerticalOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversalTest.java)
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* [ZigzagTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/ZigzagTraversalTest.java)
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* divideandconquer
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* [BinaryExponentiationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/BinaryExponentiationTest.java)
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* [ClosestPairTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/ClosestPairTest.java)
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* [SkylineAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/SkylineAlgorithmTest.java)
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* [StrassenMatrixMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/StrassenMatrixMultiplicationTest.java)
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* dynamicprogramming
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* [MinimizingLatenessTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/MinimizingLatenessTest.java)
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* io
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* [BufferedReaderTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/io/BufferedReaderTest.java)
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* lineclipping
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* [CohenSutherlandTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/lineclipping/CohenSutherlandTest.java)
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* [LiangBarskyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/lineclipping/LiangBarskyTest.java)
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* maths
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* [AbsoluteMaxTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/AbsoluteMaxTest.java)
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* [AbsoluteMinTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/AbsoluteMinTest.java)
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* [QueueUsingTwoStacksTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/QueueUsingTwoStacksTest.java)
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* [RemoveDuplicateFromStringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/RemoveDuplicateFromStringTest.java)
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* [ReverseStackUsingRecursionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ReverseStackUsingRecursionTest.java)
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* [SkylineProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/SkylineProblemTest.java)
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* [TestPrintMatrixInSpiralOrder](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/TestPrintMatrixInSpiralOrder.java)
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* [TwoPointersTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/TwoPointersTest.java)
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* [WorstFitCPUTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/WorstFitCPUTest.java)
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* Recursion
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* [GenerateSubsetsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/Recursion/GenerateSubsetsTest.java)
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* scheduling
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* [FCFSSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/FCFSSchedulingTest.java)
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* [HighestResponseRatioNextSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/HighestResponseRatioNextSchedulingTest.java)
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* [MLFQSchedulerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/MLFQSchedulerTest.java)
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* [PreemptivePrioritySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/PreemptivePrioritySchedulingTest.java)
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* [RRSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/RRSchedulingTest.java)
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* [SJFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SJFSchedulingTest.java)

‎src/main/java/com/thealgorithms/backtracking/WordSearch.java

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package com.thealgorithms.backtracking;
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/*
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Word Search Problem (https://en.wikipedia.org/wiki/Word_search)
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Given an m x n grid of characters board and a string word, return true if word exists in the grid.
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The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are
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those horizontally or vertically neighboring. The same letter cell may not be used more than once.
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For example,
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Given board =
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[
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['A','B','C','E'],
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['S','F','C','S'],
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['A','D','E','E']
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]
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word = "ABCCED", -> returns true,
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word = "SEE", -> returns true,
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word = "ABCB", -> returns false.
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*/
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/*
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Solution
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Depth First Search in matrix (as multiple sources possible) with backtracking
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like finding cycle in a directed graph. Maintain a record of path
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Tx = O(m * n * 3^L): for each cell, we look at 3 options (not 4 as that one will be visited), we
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do it L times Sx = O(L) : stack size is max L
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*/
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/**
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* Word Search Problem
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*
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* This class solves the word search problem where given an m x n grid of characters (board)
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* and a target word, the task is to check if the word exists in the grid.
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* The word can be constructed from sequentially adjacent cells (horizontally or vertically),
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* and the same cell may not be used more than once in constructing the word.
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*
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* Example:
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* - For board =
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* [
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* ['A','B','C','E'],
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* ['S','F','C','S'],
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* ['A','D','E','E']
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* ]
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* and word = "ABCCED", -> returns true
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* and word = "SEE", -> returns true
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* and word = "ABCB", -> returns false
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*
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* Solution:
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* - Depth First Search (DFS) with backtracking is used to explore possible paths from any cell
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* matching the first letter of the word. DFS ensures that we search all valid paths, while
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* backtracking helps in reverting decisions when a path fails to lead to a solution.
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*
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* Time Complexity: O(m * n * 3^L)
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* - m = number of rows in the board
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* - n = number of columns in the board
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* - L = length of the word
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* - For each cell, we look at 3 possible directions (since we exclude the previously visited direction),
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* and we do this for L letters.
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*
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* Space Complexity: O(L)
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* - Stack space for the recursive DFS function, where L is the maximum depth of recursion (length of the word).
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*/
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public class WordSearch {
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private final int[] dx = {0, 0, 1, -1};
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private final int[] dy = {1, -1, 0, 0};
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private boolean[][] visited;
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private char[][] board;
3842
private String word;
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/**
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* Checks if the given (x, y) coordinates are valid positions in the board.
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*
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* @param x The row index.
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* @param y The column index.
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* @return True if the coordinates are within the bounds of the board; false otherwise.
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*/
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private boolean isValid(int x, int y) {
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return x >= 0 && x < board.length && y >= 0 && y < board[0].length;
4253
}
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/**
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* Performs Depth First Search (DFS) from the cell (x, y)
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* to search for the next character in the word.
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*
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* @param x The current row index.
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* @param y The current column index.
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* @param nextIdx The index of the next character in the word to be matched.
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* @return True if a valid path is found to match the remaining characters of the word; false otherwise.
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*/
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private boolean doDFS(int x, int y, int nextIdx) {
4565
visited[x][y] = true;
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if (nextIdx == word.length()) {
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return true;
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}
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for (int i = 0; i < 4; ++i) {
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int xi = x + dx[i];
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int yi = y + dy[i];
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}
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}
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}
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visited[x][y] = false;
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visited[x][y] = false; // Backtrack
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return false;
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}
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/**
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* Main function to check if the word exists in the board. It initiates DFS from any
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* cell that matches the first character of the word.
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*
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* @param board The 2D grid of characters (the board).
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* @param word The target word to search for in the board.
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* @return True if the word exists in the board; false otherwise.
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*/
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public boolean exist(char[][] board, String word) {
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this.board = board;
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this.word = word;

‎src/main/java/com/thealgorithms/bitmanipulation/CountSetBits.java

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Original file line numberDiff line numberDiff line change
@@ -48,4 +48,32 @@ public long countSetBits(long num) {
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}
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return cnt;
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}
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/**
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* This approach takes O(1) running time to count the set bits, but requires a pre-processing.
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*
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* So, we divide our 32-bit input into 8-bit chunks, with four chunks. We have 8 bits in each chunk.
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*
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* Then the range is from 0-255 (0 to 2^7).
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* So, we may need to count set bits from 0 to 255 in individual chunks.
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*
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* @param num takes a long number
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* @return the count of set bits in the binary equivalent
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*/
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public int lookupApproach(int num) {
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int[] table = new int[256];
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table[0] = 0;
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for (int i = 1; i < 256; i++) {
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table[i] = (i & 1) + table[i >> 1]; // i >> 1 equals to i/2
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}
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int res = 0;
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for (int i = 0; i < 4; i++) {
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res += table[num & 0xff];
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num >>= 8;
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}
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return res;
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}
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}

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