I need this as a C++ Program

A teacher has 20 students who have taken 4 tests. The teacher uses the following grading system to assign a letter grade to a student, based on the average of his or her four test scored: Test Score Letter Grade 90 100 A 80 - 89 B 70 79 C 60 69 D 0 59 F Write a program class that uses a String array object to hold the 20 students names, an array containing 20 groups of four doubles to hold each students set of test scores. The program class should have methods that return a specific students name, the average test score and a letter grade based on the array. Demonstrate the class in a program that allows the user to enter each students name and his or her four test scores. It should then display each students average test score and letter grade. In addition create an average score over the entire class for each test and an average over all for all tests for all students and display these values Input can be typed in via the keyboard or entered through a data file containing the information on the next page. Input validation: Do not accept test scores less than zero or greater than 100.