C++that prepares graduating students from faculty of engineering for a licensing exam to be registered engineers

We have following results of a course with exam:
75 of the students who completed this course took the exam. We want to know how well the students did in the examination and are given the scores of 75 students. We want to write a program that summarizes and analyzes the results the following way:
1.	Use random number generator Use 5 (Matric/Identification number of only five digits).
2.	Input each test result (i.e., raw marks). Display the prompting message "Enter result" each time the program requests another test result. a) You are to enter the raw score and categorize it as follows:
i. 90 and above is A
ii. 89-80 is B
iii. 79-70 is C
iv. 69- 60 is D
v. 59 and below is E
3.	Count the number of test results of each type.
4.	Further categorize the result into Pass or Fail (a P or an F)
i. All As, Bs, Cs and Ds are under the P category while E is under F category.
ii. Next to each matric/identification number is written a P if the student passed the exam or an F if the student failed.
5.	Display a summary of the test results indicating the number of students who passed and the number who failed.
6.	Program should restrict user from entering invalid marks (char, negative number, above 100 etc.)