Skip to content
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions DIRECTORY.md
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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)
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,58 @@
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;
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
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));
}
}