CSCE 240 Homework 2 

CSCE 240 Homework 2 
You shall submit a zipped, and only zipped, archive of your homework directory,
hw2. The directory shall contain, at a minimum, the files hw2/parse scores.cc and
hw2/parse scores.h. Name the archive submission file hw2.zip
I will use my own makefile and test files to compile and link to your
hw2/parse scores.cc and hw2/parse scores.h files. You must submit, at least, these
two files.
Now that you have learned to use functions and arrays in C++, you are able build a C++ API library. The
functions must accept arrays of strings which provided by functional unit tests in the directory.
These functions will parse an arrays of strings into meaningful values. An array of strings will have the
following format:
{ student id, number of grades, grade 0, grade 1, grade n }
Such that a possible array would be:
{ ”flast”, ”3”, ”93.2”, ”88.1”, ”97.6” }
Read the provided header file documentation for instructions on how the functions should behave. For
more details, you must open and read the provided tests. Students asking questions which can be answered
by reading the tests will be referred to the tests.
Notes:
Global variables should be avoided because this is an exercise in functional programming. Global variables
are often a lazy way of avoiding classes, which are not needed for this task.
Conversion from strings to numeric values can be accomplished with functions such as: ˆstd::stoi and ˆstd::stod.
Their documentation can be found on cplusplus.com
Errors occur in three ways:
1. Truncation errors: these are detected by counting: ˆAny correct input array must have at least two elements: student id and number of grades. ˆThe array size given to a function will be correct. This implies that your array might specify more
grades than actually exist. Consider the following parameters:
({ ”gsmith”, ”3”, ”89.0”, ”77.1” }, 4)
The error can be detected when number of grades is parsed and converted. There is no way
for a third grade to exist because the total array size is 4.
2. Validation errors: The format of the data is as follows and any deviation should be considered a
format error. ˆnumber of students: non-negative integer ˆstudent ids: non-negative integer
CSCE 240 Homework 2 Page 2 of 2 ˆnumber of student grades: non-negative integer ˆstudent grade: non-negative floating point (use double precision)
3. Corruption errors: sometimes the values get corrupted. Though there is no way of knowing whether
an ID is corrupt (because all IDS of length one or more are valid) the numerics can be detected.
Consider the parameters:
({ ”gsmith”, ”/3”, ”8*.0”, ”77dot1” }, 4)
If using std::stoi or std::stod, you can check for these errors by catching the exceptions those
functions generate:
#include <stdexcept> // std::invalid_argument
#include <string> // std::stoi, std::stod
.
.
.
try {
student_no = std::stoi(input[index]);
} catch (const std::invalid_argument& exception) {
return false; // non-numeric student number
}
Testing and Points
You are provided a basic test app which should be used to ensure that your code is somewhat correct.
I would suggest a more rigorous testing scheme. Your code must behave as indicated in the documentation.
Passing the tests is not enough to guarantee full credit.
The point breakdown is as follows: ˆCompilation: 0.25 points per test, 1.0 in total (15% penalty) ˆGetId: 1 point ˆGetGrade: 2.5 points ˆGetGradeCount: 1 point ˆGetMaxGrade: 2.5 points ˆStyle & Documentation: 2 points
Late assignments will lose 10% per day late, with no assignment begin accepted after 3 days (at 70% reduction in points).
Check your syllabus for the breakdown of grading.
The End.