public void FirstUniqueChar_abcdabbdddd_Should_Return_2()
        {
            // Arrange

            // Act
            var result = StringQuestions.FirstUniqueChar("abcdabbdddd");

            // Assert
            Assert.AreEqual(2, result);
        }
        public void FirstUniqueChar_loveleetcode_Should_Return_2()
        {
            // Arrange

            // Act
            var result = StringQuestions.FirstUniqueChar("loveleetcode");

            // Assert
            Assert.AreEqual(2, result);
        }