Lab 9

1) Write a program to read in a positive integer n and then to generate n 
random grades (use srand) between 0 and 100 and to write them to a 
file whose name is 
entered by the user.
2) Write a program to read in a name of a file that contains integral 
grades (use the file you created in #1 above). Put the grades in an array 
(make the maximum size 100). Then search the array for the grade 87 (and 
print how many times 87 appears in the array). Also, print the array.
3) Declare an array of type int and maximum size 100. Read the actual size 
of the array from the keyboard and then read the elements of the array 
from the keyboard, and then calculate the maximum grade and the average 
grade in the array.