Add tests, remove main in IterativeTernarySearch (#5668)

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

@@ -0,0 +1,117 @@
+package com.thealgorithms.searches;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for the IterativeTernarySearch class.
+ */
+class IterativeTernarySearchTest {
+
+    /**
+     * Test for basic ternary search functionality when the element is found.
+     */
+    @Test
+    void testTernarySearchFound() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512};
+        Integer key = 128;
+        int expectedIndex = 7; // Index of the key in the array
+        assertEquals(expectedIndex, ternarySearch.find(array, key), "The index of the found element should be 7.");
+    }
+
+    /**
+     * Test for ternary search when the element is not present in the array.
+     */
+    @Test
+    void testTernarySearchNotFound() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1, 2, 4, 8, 16};
+        Integer key = 6; // Element not present in the array
+        assertEquals(-1, ternarySearch.find(array, key), "The element should not be found in the array.");
+    }
+
+    /**
+     * Test for ternary search with the first element as the key.
+     */
+    @Test
+    void testTernarySearchFirstElement() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1, 2, 4, 8, 16};
+        Integer key = 1; // First element
+        assertEquals(0, ternarySearch.find(array, key), "The index of the first element should be 0.");
+    }
+
+    /**
+     * Test for ternary search with the last element as the key.
+     */
+    @Test
+    void testTernarySearchLastElement() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1, 2, 4, 8, 16};
+        Integer key = 16; // Last element
+        assertEquals(4, ternarySearch.find(array, key), "The index of the last element should be 4.");
+    }
+
+    /**
+     * Test for ternary search with a single element present.
+     */
+    @Test
+    void testTernarySearchSingleElementFound() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1};
+        Integer key = 1; // Only element present
+        assertEquals(0, ternarySearch.find(array, key), "The index of the single element should be 0.");
+    }
+
+    /**
+     * Test for ternary search with a single element not present.
+     */
+    @Test
+    void testTernarySearchSingleElementNotFound() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {1};
+        Integer key = 2; // Key not present
+        assertEquals(-1, ternarySearch.find(array, key), "The element should not be found in the array.");
+    }
+
+    /**
+     * Test for ternary search with an empty array.
+     */
+    @Test
+    void testTernarySearchEmptyArray() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = {}; // Empty array
+        Integer key = 1; // Key not present
+        assertEquals(-1, ternarySearch.find(array, key), "The element should not be found in an empty array.");
+    }
+
+    /**
+     * Test for ternary search on a large array.
+     */
+    @Test
+    void testTernarySearchLargeArray() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = new Integer[10000];
+        for (int i = 0; i < array.length; i++) {
+            array[i] = i * 2;
+        } // Array from 0 to 19998, step 2
+        Integer key = 9998; // Present in the array
+        assertEquals(4999, ternarySearch.find(array, key), "The index of the found element should be 4999.");
+    }
+
+    /**
+     * Test for ternary search on large array with a non-existent key.
+     */
+    @Test
+    void testTernarySearchLargeArrayNotFound() {
+        IterativeTernarySearch ternarySearch = new IterativeTernarySearch();
+        Integer[] array = new Integer[10000];
+        for (int i = 0; i < array.length; i++) {
+            array[i] = i * 2;
+        } // Array from 0 to 19998, step 2
+        Integer key = 9999; // Key not present
+        assertEquals(-1, ternarySearch.find(array, key), "The element should not be found in the array.");
+    }
+}