Write a program that randomly generates 20 test scores, between 50 - 100, and store them into an array Include two overloaded functions with the following headers and requirements: a. Headers: double sum(const double TestScores[], int ArraySize, int & IndexHighestScore, int & IndexLowestScore) int sum(const int TestScores[]. int ArraySize, int & IndexHighestScore, int & IndexLowestScore) b. Requirements: - Reject outlets the highest and the lowset score are omitted. Therefore, ibkt 18 scores are to be sum and be used in finding the average score. - Tese functions will retain of the indices (pass by reference) of the highest and lowest scores in the array. Include two overloaded functions that return a letter grade of a score with the following headers and requirements: a. Header char LetterGrade(int testScore) char LetterGare(double testScore) b. requirements: Determine and return the letter grade baso on the test score(pass by value) following: testScore > = 90, LetterGrade is 'A' testScore > = 80 and = 70 and = 60 and