Add Boruvka's algorithm to find Minimum Spanning Tree (#4964)
This commit is contained in:
Niklas Hoefflin
GitHub
parent
9bebcee5c7
commit
e759544c33
20
DIRECTORY.md
20
DIRECTORY.md
@ -19,6 +19,7 @@
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* [PowerSum](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/PowerSum.java)
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* [WordSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/WordSearch.java)
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* bitmanipulation
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* [BitSwap](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BitSwap.java)
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* [HighestSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/HighestSetBit.java)
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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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@ -81,6 +82,8 @@
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* [LFUCache](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/caches/LFUCache.java)
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* [LRUCache](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/caches/LRUCache.java)
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* [MRUCache](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/caches/MRUCache.java)
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* crdt
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* [GCounter](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/crdt/GCounter.java)
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* disjointsetunion
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* [DisjointSetUnion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/disjointsetunion/DisjointSetUnion.java)
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* [Node](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/disjointsetunion/Node.java)
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@ -90,6 +93,7 @@
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* [A Star](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/A_Star.java)
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* [BellmanFord](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/BellmanFord.java)
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* [BipartiteGrapfDFS](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/BipartiteGrapfDFS.java)
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* [BoruvkaAlgorithm](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/BoruvkaAlgorithm.java)
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* [ConnectedComponent](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/ConnectedComponent.java)
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* [Cycles](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/Cycles.java)
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* [DIJSKSTRAS ALGORITHM](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/graphs/DIJSKSTRAS_ALGORITHM.java)
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@ -239,6 +243,7 @@
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* [SubsetCount](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/SubsetCount.java)
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* [SubsetSum](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/SubsetSum.java)
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* [Sum Of Subset](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/Sum_Of_Subset.java)
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* [Tribonacci](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/Tribonacci.java)
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* [UniquePaths](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/UniquePaths.java)
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* [WildcardMatching](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/WildcardMatching.java)
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* [WineProblem](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/WineProblem.java)
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@ -281,7 +286,9 @@
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* [FFT](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FFT.java)
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* [FFTBluestein](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FFTBluestein.java)
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* [FibonacciJavaStreams](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FibonacciJavaStreams.java)
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* [FibonacciLoop](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FibonacciLoop.java)
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* [FibonacciNumberCheck](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FibonacciNumberCheck.java)
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* [FibonacciNumberGoldenRation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FibonacciNumberGoldenRation.java)
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* [FindKthNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FindKthNumber.java)
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* [FindMax](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FindMax.java)
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* [FindMaxRecursion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/FindMaxRecursion.java)
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@ -307,6 +314,7 @@
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* [LongDivision](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/LongDivision.java)
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* [LucasSeries](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/LucasSeries.java)
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* [MagicSquare](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/MagicSquare.java)
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* [MatrixRank](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/MatrixRank.java)
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* [MatrixUtil](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/MatrixUtil.java)
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* [MaxValue](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/MaxValue.java)
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* [Means](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/Means.java)
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@ -359,6 +367,7 @@
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* misc
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* [ColorContrastRatio](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/ColorContrastRatio.java)
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* [InverseOfMatrix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/InverseOfMatrix.java)
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* [MapReduce](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/MapReduce.java)
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* [matrixTranspose](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/matrixTranspose.java)
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* [MedianOfMatrix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/MedianOfMatrix.java)
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* [MedianOfRunningArray](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/MedianOfRunningArray.java)
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@ -564,6 +573,7 @@
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* [PowerSumTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/PowerSumTest.java)
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* [WordSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/WordSearchTest.java)
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* bitmanipulation
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* [BitSwapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BitSwapTest.java)
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* [HighestSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/HighestSetBitTest.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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@ -605,9 +615,12 @@
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* [LFUCacheTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/caches/LFUCacheTest.java)
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* [LRUCacheTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/caches/LRUCacheTest.java)
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* [MRUCacheTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/caches/MRUCacheTest.java)
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* crdt
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* [GCounterTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/crdt/GCounterTest.java)
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* disjointsetunion
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* [DisjointSetUnionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/disjointsetunion/DisjointSetUnionTest.java)
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* graphs
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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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* [HamiltonianCycleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/HamiltonianCycleTest.java)
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* [KosarajuTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/KosarajuTest.java)
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* [TarjansAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/graphs/TarjansAlgorithmTest.java)
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@ -666,6 +679,7 @@
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* [OptimalJobSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/OptimalJobSchedulingTest.java)
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* [PartitionProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/PartitionProblemTest.java)
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* [SubsetCountTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/SubsetCountTest.java)
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* [TribonacciTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/TribonacciTest.java)
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* [UniquePathsTests](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/UniquePathsTests.java)
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* [WildcardMatchingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/WildcardMatchingTest.java)
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* geometry
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@ -700,7 +714,9 @@
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* [FastInverseSqrtTests](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FastInverseSqrtTests.java)
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* [FFTTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FFTTest.java)
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* [FibonacciJavaStreamsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FibonacciJavaStreamsTest.java)
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* [FibonacciLoopTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FibonacciLoopTest.java)
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* [FibonacciNumberCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FibonacciNumberCheckTest.java)
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* [FibonacciNumberGoldenRationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FibonacciNumberGoldenRationTest.java)
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* [FindMaxRecursionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FindMaxRecursionTest.java)
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* [FindMaxTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FindMaxTest.java)
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* [FindMinRecursionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/FindMinRecursionTest.java)
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@ -719,6 +735,7 @@
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* [LiouvilleLambdaFunctionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LiouvilleLambdaFunctionTest.java)
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* [LongDivisionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LongDivisionTest.java)
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* [LucasSeriesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LucasSeriesTest.java)
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* [MatrixRankTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/MatrixRankTest.java)
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* [MaxValueTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/MaxValueTest.java)
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* [MeansTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/MeansTest.java)
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* [MedianTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/MedianTest.java)
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@ -755,6 +772,7 @@
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* [TwinPrimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/TwinPrimeTest.java)
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* [VolumeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/VolumeTest.java)
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* misc
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* [MapReduceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MapReduceTest.java)
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* [MedianOfMatrixtest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MedianOfMatrixtest.java)
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* [MedianOfRunningArrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MedianOfRunningArrayTest.java)
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* [MirrorOfMatrixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java)
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@ -763,6 +781,7 @@
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* others
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* [ArrayLeftRotationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ArrayLeftRotationTest.java)
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* [BestFitCPUTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/BestFitCPUTest.java)
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* [BoyerMooreTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/BoyerMooreTest.java)
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* cn
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* [HammingDistanceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/cn/HammingDistanceTest.java)
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* [ConwayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ConwayTest.java)
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@ -798,6 +817,7 @@
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* [HowManyTimesRotatedTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/HowManyTimesRotatedTest.java)
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* [KMPSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/KMPSearchTest.java)
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* [OrderAgnosticBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/OrderAgnosticBinarySearchTest.java)
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* [PerfectBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/PerfectBinarySearchTest.java)
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* [QuickSelectTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/QuickSelectTest.java)
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* [RabinKarpAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RabinKarpAlgorithmTest.java)
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* [RecursiveBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RecursiveBinarySearchTest.java)
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@ -0,0 +1,217 @@
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package com.thealgorithms.datastructures.graphs;
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import java.util.ArrayList;
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import java.util.List;
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/**
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* Boruvka's algorithm to find Minimum Spanning Tree
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* (https://en.wikipedia.org/wiki/Bor%C5%AFvka%27s_algorithm)
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*
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* @author itakurah (https://github.com/itakurah)
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*/
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final class BoruvkaAlgorithm {
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private BoruvkaAlgorithm() {
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}
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/**
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* Represents an edge in the graph
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*/
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static class Edge {
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final int src;
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final int dest;
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final int weight;
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Edge(final int src, final int dest, final int weight) {
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this.src = src;
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this.dest = dest;
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this.weight = weight;
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}
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}
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/**
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* Represents the graph
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*/
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static class Graph {
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final int vertex;
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final List<Edge> edges;
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/**
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* Constructor for the graph
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*
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* @param vertex number of vertices
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* @param edges list of edges
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*/
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Graph(final int vertex, final List<Edge> edges) {
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if (vertex < 0) {
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throw new IllegalArgumentException("Number of vertices must be positive");
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}
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if (edges == null || edges.isEmpty()) {
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throw new IllegalArgumentException("Edges list must not be null or empty");
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}
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for (final var edge : edges) {
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checkEdgeVertices(edge.src, vertex);
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checkEdgeVertices(edge.dest, vertex);
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}
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this.vertex = vertex;
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this.edges = edges;
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}
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}
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/**
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* Represents a subset for Union-Find operations
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*/
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private static class Component {
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int parent;
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int rank;
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Component(final int parent, final int rank) {
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this.parent = parent;
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this.rank = rank;
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}
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}
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/**
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* Represents the state of Union-Find components and the result list
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*/
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private static class BoruvkaState {
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List<Edge> result;
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Component[] components;
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final Graph graph;
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BoruvkaState(final Graph graph) {
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this.result = new ArrayList<>();
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this.components = initializeComponents(graph);
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this.graph = graph;
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}
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/**
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* Adds the cheapest edges to the result list and performs Union operation on the subsets.
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*
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* @param cheapest Array containing the cheapest edge for each subset.
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*/
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void merge(final Edge[] cheapest) {
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for (int i = 0; i < graph.vertex; ++i) {
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if (cheapest[i] != null) {
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final var component1 = find(components, cheapest[i].src);
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final var component2 = find(components, cheapest[i].dest);
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if (component1 != component2) {
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result.add(cheapest[i]);
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union(components, component1, component2);
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}
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}
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}
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}
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/**
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* Checks if there are more edges to add to the result list
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*
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* @return true if there are more edges to add, false otherwise
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*/
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boolean hasMoreEdgesToAdd() {
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return result.size() < graph.vertex - 1;
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}
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/**
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* Computes the cheapest edges for each subset in the Union-Find structure.
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*
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* @return an array containing the cheapest edge for each subset.
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*/
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private Edge[] computeCheapestEdges() {
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Edge[] cheapest = new Edge[graph.vertex];
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for (final var edge : graph.edges) {
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final var set1 = find(components, edge.src);
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final var set2 = find(components, edge.dest);
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if (set1 != set2) {
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if (cheapest[set1] == null || edge.weight < cheapest[set1].weight) {
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cheapest[set1] = edge;
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}
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if (cheapest[set2] == null || edge.weight < cheapest[set2].weight) {
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cheapest[set2] = edge;
|
||||
}
|
||||
}
|
||||
}
|
||||
return cheapest;
|
||||
}
|
||||
|
||||
/**
|
||||
* Initializes subsets for Union-Find
|
||||
*
|
||||
* @param graph the graph
|
||||
* @return the initialized subsets
|
||||
*/
|
||||
private static Component[] initializeComponents(final Graph graph) {
|
||||
Component[] components = new Component[graph.vertex];
|
||||
for (int v = 0; v < graph.vertex; ++v) {
|
||||
components[v] = new Component(v, 0);
|
||||
}
|
||||
return components;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Finds the parent of the subset using path compression
|
||||
*
|
||||
* @param components array of subsets
|
||||
* @param i index of the subset
|
||||
* @return the parent of the subset
|
||||
*/
|
||||
static int find(final Component[] components, final int i) {
|
||||
if (components[i].parent != i) {
|
||||
components[i].parent = find(components, components[i].parent);
|
||||
}
|
||||
return components[i].parent;
|
||||
}
|
||||
|
||||
/**
|
||||
* Performs the Union operation for Union-Find
|
||||
*
|
||||
* @param components array of subsets
|
||||
* @param x index of the first subset
|
||||
* @param y index of the second subset
|
||||
*/
|
||||
static void union(Component[] components, final int x, final int y) {
|
||||
final int xroot = find(components, x);
|
||||
final int yroot = find(components, y);
|
||||
|
||||
if (components[xroot].rank < components[yroot].rank) {
|
||||
components[xroot].parent = yroot;
|
||||
} else if (components[xroot].rank > components[yroot].rank) {
|
||||
components[yroot].parent = xroot;
|
||||
} else {
|
||||
components[yroot].parent = xroot;
|
||||
components[xroot].rank++;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Boruvka's algorithm to find the Minimum Spanning Tree
|
||||
*
|
||||
* @param graph the graph
|
||||
* @return list of edges in the Minimum Spanning Tree
|
||||
*/
|
||||
static List<Edge> boruvkaMST(final Graph graph) {
|
||||
var boruvkaState = new BoruvkaState(graph);
|
||||
|
||||
while (boruvkaState.hasMoreEdgesToAdd()) {
|
||||
final var cheapest = boruvkaState.computeCheapestEdges();
|
||||
boruvkaState.merge(cheapest);
|
||||
}
|
||||
return boruvkaState.result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Checks if the edge vertices are in a valid range
|
||||
*
|
||||
* @param vertex the vertex to check
|
||||
* @param upperBound the upper bound for the vertex range
|
||||
*/
|
||||
private static void checkEdgeVertices(final int vertex, final int upperBound) {
|
||||
if (vertex < 0 || vertex >= upperBound) {
|
||||
throw new IllegalArgumentException("Edge vertex out of range");
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,191 @@
|
||||
package com.thealgorithms.datastructures.graphs;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.*;
|
||||
|
||||
import com.thealgorithms.datastructures.graphs.BoruvkaAlgorithm.Graph;
|
||||
import java.util.ArrayList;
|
||||
import java.util.List;
|
||||
import org.junit.jupiter.api.Test;
|
||||
|
||||
public class BoruvkaAlgorithmTest {
|
||||
@Test
|
||||
public void testBoruvkaMSTV9E14() {
|
||||
List<BoruvkaAlgorithm.Edge> edges = new ArrayList<>();
|
||||
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 1, 10));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 2, 12));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(1, 2, 9));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(1, 3, 8));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(2, 4, 3));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(2, 5, 1));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(4, 5, 3));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(4, 3, 7));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(3, 6, 8));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(3, 7, 5));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(5, 7, 6));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(6, 7, 9));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(6, 8, 2));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(7, 8, 11));
|
||||
|
||||
final var graph = new Graph(9, edges);
|
||||
/**
|
||||
* Adjacency matrix
|
||||
* 0 1 2 3 4 5 6 7 8
|
||||
* 0 0 10 12 0 0 0 0 0 0
|
||||
* 1 10 0 9 8 0 0 0 0 0
|
||||
* 2 12 9 0 0 3 1 0 0 0
|
||||
* 3 0 8 0 0 7 0 8 5 0
|
||||
* 4 0 0 3 7 0 3 0 0 0
|
||||
* 5 0 0 1 0 3 0 0 6 0
|
||||
* 6 0 0 0 8 0 0 0 9 2
|
||||
* 7 0 0 0 5 0 6 9 0 11
|
||||
* 8 0 0 0 0 0 0 2 11 0
|
||||
*/
|
||||
final var result = BoruvkaAlgorithm.boruvkaMST(graph);
|
||||
assertEquals(8, result.size());
|
||||
assertEquals(43, computeTotalWeight(result));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testBoruvkaMSTV2E1() {
|
||||
List<BoruvkaAlgorithm.Edge> edges = new ArrayList<>();
|
||||
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 1, 10));
|
||||
|
||||
final var graph = new Graph(2, edges);
|
||||
|
||||
/**
|
||||
* Adjacency matrix
|
||||
* 0 1
|
||||
* 0 0 10
|
||||
* 1 10 0
|
||||
*/
|
||||
final var result = BoruvkaAlgorithm.boruvkaMST(graph);
|
||||
assertEquals(1, result.size());
|
||||
assertEquals(10, computeTotalWeight(result));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testCompleteGraphK4() {
|
||||
List<BoruvkaAlgorithm.Edge> edges = new ArrayList<>();
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 1, 7));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 2, 2));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(0, 3, 5));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(1, 2, 3));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(1, 3, 4));
|
||||
edges.add(new BoruvkaAlgorithm.Edge(2, 3, 1));
|
||||
|
||||
final var graph = new Graph(4, edges);
|
||||
|
||||
/**
|
||||
* Adjacency matrix
|
||||
* 0 1 2 3
|
||||
* 0 0 7 2 5
|
||||
* 1 7 0 3 4
|
||||
* 2 2 3 0 1
|
||||
* 3 5 4 1 0
|
||||
*/
|
||||
final var result = BoruvkaAlgorithm.boruvkaMST(graph);
|
||||
assertEquals(3, result.size());
|
||||
assertEquals(6, computeTotalWeight(result));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testNegativeVertices() {
|
||||
Exception exception1 = assertThrows(IllegalArgumentException.class, () -> new Graph(-1, null));
|
||||
String expectedMessage = "Number of vertices must be positive";
|
||||
String actualMessage = exception1.getMessage();
|
||||
|
||||
assertTrue(actualMessage.contains(expectedMessage));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testEdgesNull() {
|
||||
Exception exception = assertThrows(IllegalArgumentException.class, () -> new Graph(0, null));
|
||||
String expectedMessage = "Edges list must not be null or empty";
|
||||
String actualMessage = exception.getMessage();
|
||||
|
||||
assertTrue(actualMessage.contains(expectedMessage));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testEdgesEmpty() {
|
||||
Exception exception = assertThrows(IllegalArgumentException.class, () -> new Graph(0, new ArrayList<>()));
|
||||
String expectedMessage = "Edges list must not be null or empty";
|
||||
String actualMessage = exception.getMessage();
|
||||
|
||||
assertTrue(actualMessage.contains(expectedMessage));
|
||||
}
|
||||
|
||||
@Test
|
||||
void testEdgesRange() {
|
||||
// Valid input
|
||||
List<BoruvkaAlgorithm.Edge> validEdges = new ArrayList<>();
|
||||
validEdges.add(new BoruvkaAlgorithm.Edge(0, 1, 2));
|
||||
validEdges.add(new BoruvkaAlgorithm.Edge(1, 2, 3));
|
||||
final var validGraph = new BoruvkaAlgorithm.Graph(3, validEdges);
|
||||
assertEquals(validEdges, validGraph.edges);
|
||||
|
||||
// Edge source out of range
|
||||
Exception exception1 = assertThrows(IllegalArgumentException.class, () -> {
|
||||
List<BoruvkaAlgorithm.Edge> invalidEdges = new ArrayList<>();
|
||||
invalidEdges.add(new BoruvkaAlgorithm.Edge(-1, 1, 2));
|
||||
final var invalidGraph = new BoruvkaAlgorithm.Graph(1, invalidEdges);
|
||||
assertEquals(invalidEdges, invalidGraph.edges);
|
||||
});
|
||||
String expectedMessage1 = "Edge vertex out of range";
|
||||
String actualMessage1 = exception1.getMessage();
|
||||
|
||||
assertTrue(actualMessage1.contains(expectedMessage1));
|
||||
|
||||
// Edge source out of range
|
||||
Exception exception2 = assertThrows(IllegalArgumentException.class, () -> {
|
||||
List<BoruvkaAlgorithm.Edge> invalidEdges = new ArrayList<>();
|
||||
invalidEdges.add(new BoruvkaAlgorithm.Edge(1, 0, 2));
|
||||
final var invalidGraph = new BoruvkaAlgorithm.Graph(1, invalidEdges);
|
||||
assertEquals(invalidEdges, invalidGraph.edges);
|
||||
});
|
||||
String expectedMessage2 = "Edge vertex out of range";
|
||||
String actualMessage2 = exception2.getMessage();
|
||||
|
||||
assertTrue(actualMessage2.contains(expectedMessage2));
|
||||
|
||||
// Edge destination out of range
|
||||
Exception exception3 = assertThrows(IllegalArgumentException.class, () -> {
|
||||
List<BoruvkaAlgorithm.Edge> invalidEdges = new ArrayList<>();
|
||||
invalidEdges.add(new BoruvkaAlgorithm.Edge(0, -1, 2));
|
||||
final var invalidGraph = new BoruvkaAlgorithm.Graph(1, invalidEdges);
|
||||
assertEquals(invalidEdges, invalidGraph.edges);
|
||||
});
|
||||
String expectedMessage3 = "Edge vertex out of range";
|
||||
String actualMessage3 = exception3.getMessage();
|
||||
|
||||
assertTrue(actualMessage3.contains(expectedMessage3));
|
||||
|
||||
// Edge destination out of range
|
||||
Exception exception4 = assertThrows(IllegalArgumentException.class, () -> {
|
||||
List<BoruvkaAlgorithm.Edge> invalidEdges = new ArrayList<>();
|
||||
invalidEdges.add(new BoruvkaAlgorithm.Edge(0, 1, 2));
|
||||
final var invalidGraph = new BoruvkaAlgorithm.Graph(1, invalidEdges);
|
||||
assertEquals(invalidEdges, invalidGraph.edges);
|
||||
});
|
||||
String expectedMessage4 = "Edge vertex out of range";
|
||||
String actualMessage4 = exception4.getMessage();
|
||||
|
||||
assertTrue(actualMessage4.contains(expectedMessage4));
|
||||
}
|
||||
|
||||
/**
|
||||
* Computes the total weight of the Minimum Spanning Tree
|
||||
*
|
||||
* @param result list of edges in the Minimum Spanning Tree
|
||||
* @return the total weight of the Minimum Spanning Tree
|
||||
*/
|
||||
int computeTotalWeight(final List<BoruvkaAlgorithm.Edge> result) {
|
||||
int totalWeight = 0;
|
||||
for (final var edge : result) {
|
||||
totalWeight += edge.weight;
|
||||
}
|
||||
return totalWeight;
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user