test: LongestValidParenthesesTest (#5416)

* test: LongestValidParenthesesTest

* checkstyle: fix formatting

---------

Co-authored-by: alxkm <alx@alx.com>

src/test/java/com/thealgorithms/dynamicprogramming/LongestValidParenthesesTest.java

@@ -0,0 +1,22 @@
+package com.thealgorithms.dynamicprogramming;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+public class LongestValidParenthesesTest {
+
+    private static Stream<Arguments> provideTestCases() {
+        return Stream.of(Arguments.of("", 0), Arguments.of("(", 0), Arguments.of(")", 0), Arguments.of("()", 2), Arguments.of("(())", 4), Arguments.of("()()", 4), Arguments.of(")(", 0), Arguments.of("(()", 2), Arguments.of("())(", 2), Arguments.of("(()())", 6), Arguments.of("(((())))", 8),
+            Arguments.of("(()))(()", 4), Arguments.of("()()()(", 6), Arguments.of("(()())()(", 8), Arguments.of("((((((", 0), Arguments.of("))))))", 0), Arguments.of("(()())(", 6), Arguments.of("))()(", 2), Arguments.of("()((()))", 8), Arguments.of("((()((())))", 10));
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideTestCases")
+    public void testLongestValidParentheses(String input, int expected) {
+        assertEquals(expected, LongestValidParentheses.getLongestValidParentheses(input));
+    }
+}