Assignment 13: Letter grades
due Monday 3/18
Some teachers give letter grades using this traditional numerical scale:
| 90-100 | 80-89 | 70-79 | 60-69 | below 60 |
| A | B | C | D | F |
Write a program that inputs a student's numerical grade and outputs the appropriate letter grade.
Also, if the grade is 100, in addition to the letter grade, also output a message congratulating the student for a perfect paper.
Use the else if construction to avoid unnecessary comparisons.
For example, if you've already determined that a score is in the A range, there's
no need to check whether it is in the B range.
Extensions
For 10 pts.: Write a program that inputs a set of student last names and number grades
from a data file, then prints a list of names and letter grades. (For help with file input, try this tutorial
(particularly the section titled "Text mode files"), or see pp. 46-47 and 134-137 in the textbook.)