From 69a142441542378083afeb974dbd46fd66ff2ec7 Mon Sep 17 00:00:00 2001 From: ANANT JAIN <139585700+anant-jain01@users.noreply.github.com> Date: Tue, 22 Oct 2024 23:02:51 +0530 Subject: [PATCH] Add StalinSort (#5738) --- .../sorts/AdaptiveMergeSort.java | 40 ++++++++++++++ .../com/thealgorithms/sorts/StalinSort.java | 21 ++++++++ .../sorts/AdaptiveMergeSortTest.java | 53 +++++++++++++++++++ .../thealgorithms/sorts/StalinSortTest.java | 53 +++++++++++++++++++ 4 files changed, 167 insertions(+) create mode 100644 src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java create mode 100644 src/main/java/com/thealgorithms/sorts/StalinSort.java create mode 100644 src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java create mode 100644 src/test/java/com/thealgorithms/sorts/StalinSortTest.java diff --git a/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java b/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java new file mode 100644 index 000000000..2c71bae8b --- /dev/null +++ b/src/main/java/com/thealgorithms/sorts/AdaptiveMergeSort.java @@ -0,0 +1,40 @@ +package com.thealgorithms.sorts; + +public class AdaptiveMergeSort implements SortAlgorithm { + @SuppressWarnings("unchecked") + public > T[] sort(T[] array) { + if (array.length <= 1) { + return array; + } + T[] aux = array.clone(); + sort(array, aux, 0, array.length - 1); + return array; + } + + private > void sort(T[] array, T[] aux, int low, int high) { + if (low >= high) { + return; + } + int mid = low + (high - low) / 2; + sort(array, aux, low, mid); + sort(array, aux, mid + 1, high); + merge(array, aux, low, mid, high); + } + + private > void merge(T[] array, T[] aux, int low, int mid, int high) { + System.arraycopy(array, low, aux, low, high - low + 1); + int i = low; + int j = mid + 1; + for (int k = low; k <= high; k++) { + if (i > mid) { + array[k] = aux[j++]; + } else if (j > high) { + array[k] = aux[i++]; + } else if (aux[j].compareTo(aux[i]) < 0) { + array[k] = aux[j++]; + } else { + array[k] = aux[i++]; + } + } + } +} diff --git a/src/main/java/com/thealgorithms/sorts/StalinSort.java b/src/main/java/com/thealgorithms/sorts/StalinSort.java new file mode 100644 index 000000000..5aaf530fd --- /dev/null +++ b/src/main/java/com/thealgorithms/sorts/StalinSort.java @@ -0,0 +1,21 @@ +package com.thealgorithms.sorts; + +public class StalinSort implements SortAlgorithm { + @SuppressWarnings("unchecked") + public > T[] sort(T[] array) { + if (array.length == 0) { + return array; + } + int currentIndex = 0; + for (int i = 1; i < array.length; i++) { + if (array[i].compareTo(array[currentIndex]) >= 0) { + currentIndex++; + array[currentIndex] = array[i]; + } + } + // Create a result array with sorted elements + T[] result = (T[]) java.lang.reflect.Array.newInstance(array.getClass().getComponentType(), currentIndex + 1); + System.arraycopy(array, 0, result, 0, currentIndex + 1); + return result; + } +} diff --git a/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java b/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java new file mode 100644 index 000000000..9d94b165d --- /dev/null +++ b/src/test/java/com/thealgorithms/sorts/AdaptiveMergeSortTest.java @@ -0,0 +1,53 @@ +package com.thealgorithms.sorts; + +import static org.junit.jupiter.api.Assertions.assertArrayEquals; + +import org.junit.jupiter.api.Test; + +public class AdaptiveMergeSortTest { + + @Test + public void testSortIntegers() { + AdaptiveMergeSort adaptiveMergeSort = new AdaptiveMergeSort(); + Integer[] input = {4, 23, 6, 78, 1, 54, 231, 9, 12}; + Integer[] expected = {1, 4, 6, 9, 12, 23, 54, 78, 231}; + Integer[] result = adaptiveMergeSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortStrings() { + AdaptiveMergeSort adaptiveMergeSort = new AdaptiveMergeSort(); + String[] input = {"c", "a", "e", "b", "d"}; + String[] expected = {"a", "b", "c", "d", "e"}; + String[] result = adaptiveMergeSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortWithDuplicates() { + AdaptiveMergeSort adaptiveMergeSort = new AdaptiveMergeSort(); + Integer[] input = {1, 3, 2, 2, 5, 4}; + Integer[] expected = {1, 2, 2, 3, 4, 5}; + Integer[] result = adaptiveMergeSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortEmptyArray() { + AdaptiveMergeSort adaptiveMergeSort = new AdaptiveMergeSort(); + Integer[] input = {}; + Integer[] expected = {}; + Integer[] result = adaptiveMergeSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortSingleElement() { + AdaptiveMergeSort adaptiveMergeSort = new AdaptiveMergeSort(); + Integer[] input = {42}; + Integer[] expected = {42}; + Integer[] result = adaptiveMergeSort.sort(input); + assertArrayEquals(expected, result); + } +} diff --git a/src/test/java/com/thealgorithms/sorts/StalinSortTest.java b/src/test/java/com/thealgorithms/sorts/StalinSortTest.java new file mode 100644 index 000000000..ee9c61379 --- /dev/null +++ b/src/test/java/com/thealgorithms/sorts/StalinSortTest.java @@ -0,0 +1,53 @@ +package com.thealgorithms.sorts; + +import static org.junit.jupiter.api.Assertions.assertArrayEquals; + +import org.junit.jupiter.api.Test; + +public class StalinSortTest { + + @Test + public void testSortIntegers() { + StalinSort stalinSort = new StalinSort(); + Integer[] input = {4, 23, 6, 78, 1, 54, 231, 9, 12}; + Integer[] expected = {4, 23, 78, 231}; + Integer[] result = stalinSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortStrings() { + StalinSort stalinSort = new StalinSort(); + String[] input = {"c", "a", "e", "b", "d"}; + String[] expected = {"c", "e"}; + String[] result = stalinSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortWithDuplicates() { + StalinSort stalinSort = new StalinSort(); + Integer[] input = {1, 3, 2, 2, 5, 4}; + Integer[] expected = {1, 3, 5}; + Integer[] result = stalinSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortEmptyArray() { + StalinSort stalinSort = new StalinSort(); + Integer[] input = {}; + Integer[] expected = {}; + Integer[] result = stalinSort.sort(input); + assertArrayEquals(expected, result); + } + + @Test + public void testSortSingleElement() { + StalinSort stalinSort = new StalinSort(); + Integer[] input = {42}; + Integer[] expected = {42}; + Integer[] result = stalinSort.sort(input); + assertArrayEquals(expected, result); + } +}