public Tuple <int, int[]> RetrieveTestCase(int testCaseNumber)
{
if (testCaseNumber < 1 || testCaseNumber > input.Length / 2)
{
throw new ArgumentOutOfRangeException(nameof(testCaseNumber), "invalid index. Index should count from 1 to number of test cases.");
}
int numberOfStudentsRowIndex = (testCaseNumber * 2) - 1;
int studentRanksRowIndex = numberOfStudentsRowIndex + 1;
if (!validator.IsNumOfStudentsRowHasValidData(numberOfStudentsRowIndex))
{
throw new ArithmeticException($"invalid number of students at row number { numberOfStudentsRowIndex + 1 }");
}
int numberOfStudents = Convert.ToInt32(input[numberOfStudentsRowIndex]);
if (!validator.IsStudentRankRowHasValidData(studentRanksRowIndex, numberOfStudents))
{
throw new ArithmeticException($"invalid rank data for students at row number { studentRanksRowIndex + 1 }");
}
var studentRanks = TransformStudentRanksString(input[studentRanksRowIndex]);
return(Tuple.Create <int, int[]>(numberOfStudents, studentRanks));
}