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Add BandwidthAllocation algorithm (#5807)

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Hardik Pawar
2024-10-26 17:33:40 +05:30
committed by GitHub
parent 7cf568c975
commit 73416e2f0c
3 changed files with 88 additions and 0 deletions
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8
DIRECTORY.md
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@@ -320,11 +320,14 @@
* [BresenhamLine](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/BresenhamLine.java)
* [ConvexHull](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/ConvexHull.java)
* [GrahamScan](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/GrahamScan.java)
* [MidpointCircle](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/MidpointCircle.java)
* [MidpointEllipse](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/MidpointEllipse.java)
* [Point](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/geometry/Point.java)
* graph
* [StronglyConnectedComponentOptimized](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/graph/StronglyConnectedComponentOptimized.java)
* greedyalgorithms
* [ActivitySelection](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/ActivitySelection.java)
* [BandwidthAllocation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/BandwidthAllocation.java)
* [BinaryAddition](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/BinaryAddition.java)
* [CoinChange](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/CoinChange.java)
* [DigitSeparation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/DigitSeparation.java)
@@ -360,6 +363,7 @@
* [Average](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/Average.java)
* [BinaryPow](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/BinaryPow.java)
* [BinomialCoefficient](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/BinomialCoefficient.java)
* [CatalanNumbers](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/CatalanNumbers.java)
* [Ceil](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/Ceil.java)
* [ChineseRemainderTheorem](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/ChineseRemainderTheorem.java)
* [CircularConvolutionFFT](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/CircularConvolutionFFT.java)
@@ -967,10 +971,13 @@
* [BresenhamLineTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/BresenhamLineTest.java)
* [ConvexHullTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/ConvexHullTest.java)
* [GrahamScanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/GrahamScanTest.java)
* [MidpointCircleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/MidpointCircleTest.java)
* [MidpointEllipseTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/geometry/MidpointEllipseTest.java)
* graph
* [StronglyConnectedComponentOptimizedTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/graph/StronglyConnectedComponentOptimizedTest.java)
* greedyalgorithms
* [ActivitySelectionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/ActivitySelectionTest.java)
* [BandwidthAllocationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/BandwidthAllocationTest.java)
* [BinaryAdditionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/BinaryAdditionTest.java)
* [CoinChangeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/CoinChangeTest.java)
* [DigitSeparationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/DigitSeparationTest.java)
@@ -1003,6 +1010,7 @@
* [AverageTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/AverageTest.java)
* [BinaryPowTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/BinaryPowTest.java)
* [BinomialCoefficientTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/BinomialCoefficientTest.java)
* [CatalanNumbersTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/CatalanNumbersTest.java)
* [CeilTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/CeilTest.java)
* [ChineseRemainderTheoremTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/ChineseRemainderTheoremTest.java)
* [CollatzConjectureTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/CollatzConjectureTest.java)

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src/main/java/com/thealgorithms/greedyalgorithms/BandwidthAllocation.java Normal file
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package com.thealgorithms.greedyalgorithms;
import java.util.Arrays;
/**
* Class to solve the Bandwidth Allocation Problem.
* The goal is to maximize the value gained by allocating bandwidth to users.
* Example:
* Bandwidth = 10
* Users = [3, 5, 7]
* Values = [10, 20, 30]
* The maximum value achievable is 40 by allocating 3 units to user 0 and 7 units to user 2.
*
* @author Hardvan
*/
public final class BandwidthAllocation {
private BandwidthAllocation() {
}
/**
* Allocates bandwidth to maximize value.
* Steps:
* 1. Calculate the ratio of value/demand for each user.
* 2. Sort the users in descending order of the ratio.
* 3. Allocate bandwidth to users in order of the sorted list.
* 4. If the bandwidth is not enough to allocate the full demand of a user, allocate a fraction of the demand.
* 5. Return the maximum value achievable.
*
* @param bandwidth total available bandwidth to allocate
* @param users array of user demands
* @param values array of values associated with each user's demand
* @return the maximum value achievable
*/
public static int maxValue(int bandwidth, int[] users, int[] values) {
int n = users.length;
double[][] ratio = new double[n][2]; // {index, ratio}
for (int i = 0; i < n; i++) {
ratio[i][0] = i;
ratio[i][1] = (double) values[i] / users[i];
}
Arrays.sort(ratio, (a, b) -> Double.compare(b[1], a[1]));
int maxValue = 0;
for (int i = 0; i < n; i++) {
int index = (int) ratio[i][0];
if (bandwidth >= users[index]) {
maxValue += values[index];
bandwidth -= users[index];
} else {
maxValue += (int) (ratio[i][1] * bandwidth);
break;
}
}
return maxValue;
}
}

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src/test/java/com/thealgorithms/greedyalgorithms/BandwidthAllocationTest.java Normal file
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package com.thealgorithms.greedyalgorithms;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.stream.Stream;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;
public class BandwidthAllocationTest {
@ParameterizedTest
@MethodSource("bandwidthProvider")
public void testMaxValue(int capacity, int[] bandwidths, int[] values, int expected) {
assertEquals(expected, BandwidthAllocation.maxValue(capacity, bandwidths, values));
}
private static Stream<Arguments> bandwidthProvider() {
return Stream.of(Arguments.of(50, new int[] {20, 10, 30}, new int[] {40, 20, 30}, 80), Arguments.of(0, new int[] {5, 10}, new int[] {10, 20}, 0), Arguments.of(5, new int[] {5, 10}, new int[] {10, 20}, 10), Arguments.of(15, new int[] {10, 20}, new int[] {10, 25}, 18),
Arguments.of(25, new int[] {10, 15, 20}, new int[] {10, 30, 50}, 60));
}
}