diff --git a/src/main/java/com/thealgorithms/searches/JumpSearch.java b/src/main/java/com/thealgorithms/searches/JumpSearch.java index 8dcec3a819a4..7ab8b35b3202 100644 --- a/src/main/java/com/thealgorithms/searches/JumpSearch.java +++ b/src/main/java/com/thealgorithms/searches/JumpSearch.java @@ -1,56 +1,44 @@ package com.thealgorithms.searches; -import com.thealgorithms.devutils.searches.SearchAlgorithm; - /** - * An implementation of the Jump Search algorithm. - * - *

- * Jump Search is an algorithm for searching sorted arrays. It works by dividing the array - * into blocks of a fixed size (the block size is typically the square root of the array length) - * and jumping ahead by this block size to find a range where the target element may be located. - * Once the range is found, a linear search is performed within that block. - * - *

- * The Jump Search algorithm is particularly effective for large sorted arrays where the cost of - * performing a linear search on the entire array would be prohibitive. + * Implementation of Jump Search algorithm. * - *

- * Worst-case performance: O(√N)
- * Best-case performance: O(1)
- * Average performance: O(√N)
- * Worst-case space complexity: O(1) + * Time Complexity: O(√n) + * Space Complexity: O(1) * - *

- * This class implements the {@link SearchAlgorithm} interface, providing a generic search method - * for any comparable type. + * Reference: https://en.wikipedia.org/wiki/Jump_search */ -public class JumpSearch implements SearchAlgorithm { +public final class JumpSearch { + + // Prevent instantiation + private JumpSearch() { + throw new UnsupportedOperationException("Utility class"); + } - /** - * Jump Search algorithm implementation. - * - * @param array the sorted array containing elements - * @param key the element to be searched - * @return the index of {@code key} if found, otherwise -1 - */ - @Override - public > int find(T[] array, T key) { - int length = array.length; - int blockSize = (int) Math.sqrt(length); + public static int jumpSearch(int[] arr, int target) { + int n = arr.length; + int step = (int) Math.floor(Math.sqrt(n)); + int prev = 0; - int limit = blockSize; - // Jumping ahead to find the block where the key may be located - while (limit < length && key.compareTo(array[limit]) > 0) { - limit = Math.min(limit + blockSize, length - 1); + while (prev < n && arr[Math.min(step, n) - 1] < target) { + prev = step; + step += (int) Math.floor(Math.sqrt(n)); } - // Perform linear search within the identified block - for (int i = limit - blockSize; i <= limit && i < length; i++) { - if (array[i].equals(key)) { + for (int i = prev; i < Math.min(step, n); i++) { + if (arr[i] == target) { return i; } } + return -1; } + + public static int find(Integer[] arr, Integer target) { + int[] array = new int[arr.length]; + for (int i = 0; i < arr.length; i++) { + array[i] = arr[i]; + } + return jumpSearch(array, target); + } } diff --git a/src/test/java/com/thealgorithms/searches/JumpSearchTest.java b/src/test/java/com/thealgorithms/searches/JumpSearchTest.java index 3fa319b66a41..93c321b1bcd2 100644 --- a/src/test/java/com/thealgorithms/searches/JumpSearchTest.java +++ b/src/test/java/com/thealgorithms/searches/JumpSearchTest.java @@ -4,91 +4,60 @@ import org.junit.jupiter.api.Test; -/** - * Unit tests for the JumpSearch class. - */ class JumpSearchTest { - /** - * Test for finding an element present in the array. - */ @Test void testJumpSearchFound() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; - Integer key = 5; // Element to find - assertEquals(5, jumpSearch.find(array, key), "The index of the found element should be 5."); + Integer key = 5; + assertEquals(5, JumpSearch.find(array, key)); } - /** - * Test for finding the first element in the array. - */ @Test void testJumpSearchFirstElement() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; - Integer key = 0; // First element - assertEquals(0, jumpSearch.find(array, key), "The index of the first element should be 0."); + Integer key = 0; + assertEquals(0, JumpSearch.find(array, key)); } - /** - * Test for finding the last element in the array. - */ @Test void testJumpSearchLastElement() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; - Integer key = 10; // Last element - assertEquals(10, jumpSearch.find(array, key), "The index of the last element should be 10."); + Integer key = 10; + assertEquals(10, JumpSearch.find(array, key)); } - /** - * Test for finding an element not present in the array. - */ @Test void testJumpSearchNotFound() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; - Integer key = -1; // Element not in the array - assertEquals(-1, jumpSearch.find(array, key), "The element should not be found in the array."); + Integer key = -1; + assertEquals(-1, JumpSearch.find(array, key)); } - /** - * Test for finding an element in an empty array. - */ @Test void testJumpSearchEmptyArray() { - JumpSearch jumpSearch = new JumpSearch(); - Integer[] array = {}; // Empty array - Integer key = 1; // Key not present - assertEquals(-1, jumpSearch.find(array, key), "The element should not be found in an empty array."); + Integer[] array = {}; + Integer key = 1; + assertEquals(-1, JumpSearch.find(array, key)); } - /** - * Test for finding an element in a large array. - */ @Test void testJumpSearchLargeArray() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = new Integer[1000]; for (int i = 0; i < array.length; i++) { - array[i] = i * 2; // Fill the array with even numbers + array[i] = i * 2; } - Integer key = 256; // Present in the array - assertEquals(128, jumpSearch.find(array, key), "The index of the found element should be 128."); + Integer key = 256; + assertEquals(128, JumpSearch.find(array, key)); } - /** - * Test for finding an element in a large array when it is not present. - */ @Test void testJumpSearchLargeArrayNotFound() { - JumpSearch jumpSearch = new JumpSearch(); Integer[] array = new Integer[1000]; for (int i = 0; i < array.length; i++) { - array[i] = i * 2; // Fill the array with even numbers + array[i] = i * 2; } - Integer key = 999; // Key not present - assertEquals(-1, jumpSearch.find(array, key), "The element should not be found in the array."); + Integer key = 999; + assertEquals(-1, JumpSearch.find(array, key)); } }