Add Z-Algorithm for Linear-Time String Pattern Matching (#7124)

* Add Z-Algorithm (string pattern matching) with tests

* Add Z-Algorithm (string pattern matching) with tests

* Add Z-Algorithm (string pattern matching) with tests

* Fix checkstyle errors for ZAlgorithm

* Fix: clang-format and checkstyle compliance for ZAlgorithm

src/test/java/com/thealgorithms/strings/ZAlgorithmTest.java

@@ -0,0 +1,25 @@
+package com.thealgorithms.strings;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class ZAlgorithmTest {
+
+    @Test
+    void testZFunction() {
+        int[] z = ZAlgorithm.zFunction("aaaaa");
+        assertArrayEquals(new int[] {0, 4, 3, 2, 1}, z);
+    }
+
+    @Test
+    void testSearchFound() {
+        assertEquals(2, ZAlgorithm.search("abcabca", "cab"));
+    }
+
+    @Test
+    void testSearchNotFound() {
+        assertEquals(-1, ZAlgorithm.search("abcdef", "gh"));
+    }
+}