1 of 1 CSE 142, Spring 2011 Programming Assignment #4: Grades (20 points) Due Tuesday, April 26, 2011, 9:00 PM This interactive program focuses on if/else statements, Scanner, and returning values. Turn in a file named Grades.java. To use a Scanner for console input, you must import java.util.*; in your code. The program reads as input a student's grades on homework and two exams and uses them to compute the student's course grade. Below is one example log of execution from the program. This program behaves differently depending on the user input; user input is bold and underlined below. Your output should match our examples exactly given the same input. (Be mindful of spacing, such as after input prompts and between output sections.) Look at the other example logs on the course web site and on the next page to get more examples of the program's behavior. The program begins with an introduction message that briefly explains the program. The program then reads scores in three categories: homework and two exams. Each category is weighted; its points are scaled up to a fraction of the 100 percent grade for the course. As the program begins reading each category, it first prompts for the category's weight. The user begins by entering scores earned on an exam. The program asks whether the exam was curved, interpreting an answer of 1 to mean “yes” and 2 to mean “no.” If there is a curve, the program prompts for the curve amount, and the curve is added to the user's exam score. Exam scores are capped at a max of 100; for example, if the user got 95 and there was a curve of 10, the score to use would be 100. The exam's “weighted score” is printed, which is equal to the user's score multiplied by the exam's weight. Next the program prompts for data about a second exam. This behavior is the same as the behavior for the first exam. Next the user enters information about his/her homework, including the weight and how many assignments were given. For each assignment, the user enters a score and points possible. Use a cumulative sum as in textbook section 4.2. Part of the homework score comes from sections attended. We will simplify the formula to assume that each section attended is worth 3 points, up to a maximum of 20 points. Once the program has read the user information for both exams and homework, it prints the student's overall percentage earned in the course, which is the sum of the weighted scores from the three categories, as shown below: The program prints a loose guarantee about a minimum grade on the 4.0-scale the student will get in the course, based on the following scale. See the logs of execution on the course web site to see the expected output for each grade range. 85% and above: 3.0; 84.99% - 75%: 2.0; 74.99% - 60%: at least 0.7; under 60%: 0.0 After printing the guaranteed minimum grade, print a custom message of your choice about the grade. This message should be different for each grade range shown above. It should be at least 1 line of any non-offensive text you like. This program reads exam/homework scores and reports your overall course grade. Exam 1: What is its weight (0-100)? 20 Score earned? 78 Was there a curve (1=yes, 2=no)? 2 Total points = 78 / 100 Weighted score = 15.6 / 20 Exam 2: What is its weight (0-100)? 30 Score earned? 95 Was there a curve (1=yes, 2=no)? 1 How much was the curve? 10 Total points = 100 / 100 Weighted score = 30.0 / 30 Homework: What is its weight (0-100)? 50 Number of assignments? 3 Assignment 1 score and max? 14 15 Assignment 2 score and max? 17 20 Assignment 3 score and max? 19 25 How many sections did you attend? 5 Section points = 15 / 20 Total points = 65 / 80 Weighted score = 40.6 / 50 Overall percentage = 86.2 Your grade will be at least: 3.0 << your custom grade message here >>2 of 2 This program processes user input using a Scanner. You should handle the following two special cases of input: • A student can receive extra credit on an assignment; for example, 22 / 20 is a legal score. But the total homework points are capped at the max possible. For example, if a student receives 63 / 60 total, cap this to 60 / 60. • Cap exam scores at 100. If the raw or curved exam score exceeds 100, a score of 100 is used. Otherwise, you may assume the user enters valid input. When prompted for a value, the user will enter an integer, and one in a proper range. The user will enter a number of homework assignments ≥ 1, and the sum of the three weights will be exactly 100. The weight of each category will be a non-negative number. Curves will be ≥ 0. Development Strategy and Hints: • Tackle parts of the program (midterm, homework, final exam) one at a time, rather than writing the entire program at once. Write a bit of code, get it to compile, and test what you have so far. If you try to write large amounts of code without attempting to compile it, you may encounter a large list of compiler errors and/or bugs. • To compute homework scores, you will need to cumulatively sum not only the total points the student has earned, but also the total points possible on all homework assignments. See textbook section 4.2 about cumulative sums. • The homework part reads two values on one line from the Scanner. See the lecture slides for an example of this. • Many students get "cannot find symbol" compiler errors. Common mistakes include forgetting to pass / return a needed value, forgetting to store a returned value into a variable, and referring to a variable by the wrong name. • All weighted scores and grades are printed by the program with no more than 1 digit after the decimal point. Achieve this with System.out.printf. The following code prints variable x rounded to the nearest tenth: double x = 1.2345; System.out.printf("x is around %.1f in size.\n", x); // 1.2 • If you are getting scores of 0 regardless of what data the user types, you may have a problem with integer division. See Chapter 2 about types int and double, type-casting, and how to avoid integer division problems. If you have a value of type double but need to convert it into an int, use a type-cast such as the following: double d = 5.678; int i = (int) d; // 5 • Use Math.max and Math.min to
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