Add EgyptianFraction algorithm (#5804)

2025-07-06 00:54:32 +08:00 · 2024-10-26 00:53:20 +05:30
parent cebefbc8b6
commit 135fb08224
3 changed files with 66 additions and 0 deletions
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@ -321,6 +321,7 @@
            * [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)
+            * [EgyptianFraction](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/EgyptianFraction.java)
            * [FractionalKnapsack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java)
            * [GaleShapley](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/GaleShapley.java)
            * [JobSequencing](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/JobSequencing.java)
@ -351,6 +352,7 @@
            * [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)
            * [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)
            * [CollatzConjecture](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/CollatzConjecture.java)
            * [Combinations](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/Combinations.java)
@ -568,6 +570,8 @@
            * [TernarySearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/TernarySearch.java)
            * [UnionFind](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UnionFind.java)
            * [UpperBound](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/UpperBound.java)
+          * slidingwindow
+            * [MaxSumKSizeSubarray](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/slidingwindow/MaxSumKSizeSubarray.java)
          * sorts
            * [AdaptiveMergeSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java)
            * [BeadSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BeadSort.java)
@ -826,6 +830,7 @@
              * [HashMapCuckooHashingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/hashmap/HashMapCuckooHashingTest.java)
            * heaps
              * [FibonacciHeapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/heaps/FibonacciHeapTest.java)
+              * [GenericHeapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/heaps/GenericHeapTest.java)
              * [LeftistHeapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/heaps/LeftistHeapTest.java)
            * lists
              * [CircleLinkedListTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/lists/CircleLinkedListTest.java)
@ -942,6 +947,7 @@
            * [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)
+            * [EgyptianFractionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/EgyptianFractionTest.java)
            * [FractionalKnapsackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/FractionalKnapsackTest.java)
            * [GaleShapleyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/GaleShapleyTest.java)
            * [JobSequencingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/JobSequencingTest.java)
@ -969,6 +975,7 @@
            * [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)
            * [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)
            * [CombinationsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/CombinationsTest.java)
            * [ConvolutionFFTTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/ConvolutionFFTTest.java)
@ -1155,6 +1162,8 @@
            * [TestSearchInARowAndColWiseSortedMatrix](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/TestSearchInARowAndColWiseSortedMatrix.java)
            * [UnionFindTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UnionFindTest.java)
            * [UpperBoundTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/UpperBoundTest.java)
+          * slidingwindow
+            * [MaxSumKSizeSubarrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/slidingwindow/MaxSumKSizeSubarrayTest.java)
          * sorts
            * [AdaptiveMergeSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java)
            * [BeadSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BeadSortTest.java)
--- a/src/main/java/com/thealgorithms/greedyalgorithms/EgyptianFraction.java
+++ b/src/main/java/com/thealgorithms/greedyalgorithms/EgyptianFraction.java
@ -0,0 +1,35 @@
+package com.thealgorithms.greedyalgorithms;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Class to represent a fraction as a sum of unique unit fractions.
+ * Example:
+ * 2/3 = 1/2 + 1/6
+ * 3/10 = 1/4 + 1/20
+ *
+ * @author Hardvan
+ */
+public final class EgyptianFraction {
+    private EgyptianFraction() {
+    }
+
+    /**
+     * Calculates the Egyptian Fraction representation of a given fraction.
+     *
+     * @param numerator   the numerator of the fraction
+     * @param denominator the denominator of the fraction
+     * @return List of unit fractions represented as strings "1/x"
+     */
+    public static List<String> getEgyptianFraction(int numerator, int denominator) {
+        List<String> result = new ArrayList<>();
+        while (numerator != 0) {
+            int x = (int) Math.ceil((double) denominator / numerator);
+            result.add("1/" + x);
+            numerator = numerator * x - denominator;
+            denominator = denominator * x;
+        }
+        return result;
+    }
+}
--- a/src/test/java/com/thealgorithms/greedyalgorithms/EgyptianFractionTest.java
+++ b/src/test/java/com/thealgorithms/greedyalgorithms/EgyptianFractionTest.java
@ -0,0 +1,22 @@
+package com.thealgorithms.greedyalgorithms;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.List;
+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 EgyptianFractionTest {
+
+    @ParameterizedTest
+    @MethodSource("fractionProvider")
+    public void testGetEgyptianFraction(int numerator, int denominator, List<String> expected) {
+        assertEquals(expected, EgyptianFraction.getEgyptianFraction(numerator, denominator));
+    }
+
+    private static Stream<Arguments> fractionProvider() {
+        return Stream.of(Arguments.of(2, 3, List.of("1/2", "1/6")), Arguments.of(3, 10, List.of("1/4", "1/20")), Arguments.of(1, 3, List.of("1/3")), Arguments.of(1, 2, List.of("1/2")), Arguments.of(4, 13, List.of("1/4", "1/18", "1/468")));
+    }
+}