Add tests, remove main in LinearSearchThread (TheAlgorithms#5671)

Author: Hardvan

DIRECTORY.md

@@ -1010,6 +1010,7 @@
             * [JumpSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/JumpSearchTest.java)
             * [KMPSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/KMPSearchTest.java)
             * [LinearSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/LinearSearchTest.java)
+            * [LinearSearchThreadTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/LinearSearchThreadTest.java)
             * [MonteCarloTreeSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/MonteCarloTreeSearchTest.java)
             * [OrderAgnosticBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/OrderAgnosticBinarySearchTest.java)
             * [PerfectBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/PerfectBinarySearchTest.java)

src/main/java/com/thealgorithms/searches/LinearSearchThread.java

@@ -1,59 +1,57 @@
 package com.thealgorithms.searches;
 
-import java.util.Scanner;
-
+/**
+ * LinearSearchThread is a multithreaded implementation of the linear search algorithm.
+ * It creates multiple threads to search for a specific number in an array.
+ *
+ * <p>
+ * The class generates an array of random integers, prompts the user to enter a number to search for,
+ * and divides the array into four segments, each handled by a separate thread.
+ * The threads run concurrently and search for the specified number within their designated segments.
+ * Finally, it consolidates the results to determine if the number was found.
+ * </p>
+ *
+ * <p>
+ * Example usage:
+ * 1. The program will output the generated array.
+ * 2. The user will be prompted to input a number to search for.
+ * 3. The program will display whether the number was found in the array.
+ * </p>
+ */
 public final class LinearSearchThread {
     private LinearSearchThread() {
     }
-
-    public static void main(String[] args) {
-        int[] list = new int[200];
-        for (int j = 0; j < list.length; j++) {
-            list[j] = (int) (Math.random() * 100);
-        }
-        for (int y : list) {
-            System.out.print(y + " ");
-        }
-        System.out.println();
-        System.out.print("Enter number to search for: ");
-        Scanner in = new Scanner(System.in);
-        int x = in.nextInt();
-        Searcher t = new Searcher(list, 0, 50, x);
-        Searcher t1 = new Searcher(list, 50, 100, x);
-        Searcher t2 = new Searcher(list, 100, 150, x);
-        Searcher t3 = new Searcher(list, 150, 200, x);
-        t.start();
-        t1.start();
-        t2.start();
-        t3.start();
-        try {
-            t.join();
-            t1.join();
-            t2.join();
-            t3.join();
-        } catch (InterruptedException e) {
-        }
-        boolean found = t.getResult() || t1.getResult() || t2.getResult() || t3.getResult();
-        System.out.println("Found = " + found);
-        in.close();
-    }
 }
 
+/**
+ * The Searcher class extends Thread and is responsible for searching for a specific
+ * number in a segment of an array.
+ */
 class Searcher extends Thread {
+    private final int[] arr; // The array to search in
+    private final int left; // Starting index of the segment
+    private final int right; // Ending index of the segment
+    private final int x; // The number to search for
+    private boolean found; // Result flag
 
-    private final int[] arr;
-    private final int left;
-    private final int right;
-    private final int x;
-    private boolean found;
-
+    /**
+     * Constructor to initialize the Searcher.
+     *
+     * @param arr The array to search in
+     * @param left The starting index of the segment
+     * @param right The ending index of the segment
+     * @param x The number to search for
+     */
     Searcher(int[] arr, int left, int right, int x) {
         this.arr = arr;
         this.left = left;
         this.right = right;
         this.x = x;
     }
 
+    /**
+     * The run method for the thread, performing the linear search in its segment.
+     */
     @Override
     public void run() {
         int k = left;
@@ -65,6 +63,11 @@ public void run() {
         }
     }
 
+    /**
+     * Returns whether the number was found in the segment.
+     *
+     * @return true if the number was found, false otherwise
+     */
     boolean getResult() {
         return found;
     }

src/test/java/com/thealgorithms/searches/LinearSearchThreadTest.java

@@ -0,0 +1,74 @@
+package com.thealgorithms.searches;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class LinearSearchThreadTest {
+
+    /**
+     * Test for finding an element that is present in the array.
+     */
+    @Test
+    void testSearcherFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, array.length, 5);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The element 5 should be found in the array.");
+    }
+
+    /**
+     * Test for finding an element that is not present in the array.
+     */
+    @Test
+    void testSearcherNotFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, array.length, 11);
+        searcher.start();
+        searcher.join();
+        assertFalse(searcher.getResult(), "The element 11 should not be found in the array.");
+    }
+
+    /**
+     * Test for searching a segment of the array.
+     */
+    @Test
+    void testSearcherSegmentFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, 5, 3);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The element 3 should be found in the segment.");
+    }
+
+    /**
+     * Test for searching an empty array segment.
+     */
+    @Test
+    void testSearcherEmptySegment() throws InterruptedException {
+        int[] array = {};
+        Searcher searcher = new Searcher(array, 0, 0, 1); // Empty array
+        searcher.start();
+        searcher.join();
+        assertFalse(searcher.getResult(), "The element should not be found in an empty segment.");
+    }
+
+    /**
+     * Test for searching with random numbers.
+     */
+    @Test
+    void testSearcherRandomNumbers() throws InterruptedException {
+        int size = 200;
+        int[] array = new int[size];
+        for (int i = 0; i < size; i++) {
+            array[i] = (int) (Math.random() * 100);
+        }
+        int target = array[(int) (Math.random() * size)]; // Randomly select a target that is present
+        Searcher searcher = new Searcher(array, 0, size, target);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The randomly selected target should be found in the array.");
+    }
+}