CSCE 240 Exam 1

CSCE 240 Exam 1
You must submit a zipped, and only zipped, archive of your project directory,
exam1.zip. The directory should contain, at a minimum, the files
1. problem1.cc
2. problem2.cc and problem2.h
3. problem3.cc and problem3.h
in a directory named exam1.
A different makefile will be used to make your project files.
You are provided a makefile that will build and test all problems. If you are working from
a BASH shell (it is likely called wsl if you are running WSL on windows), try typing
make problem
followed by the tab key a couple times. This will show you all possible build options for each
problem, including style tests.

CSCE 240 Exam 1 Page 2 of 4
Problem1: infix notation floating point comparator
Task: WITHOUT PROMPTING read two numbers and an operator from STDIN, using std::cin three times
or in its form:
std::cin >> value1 >> value2 >> value3;
The input will always be given as
number operator number
e.g., 2.3 == 2.3, 4.5 != 4.5, etc.
Using the operands and operators and conditional statement(s) perform the operation. Emit the string
”true” or ”false” as necessary.
DO NOT emit anything other than the result. This is a calculator. Simply emit the result of the operation. Do not prompt for input. Just write the result of the operation to STDOUT using std::cout.
The two operands can be read as floating point data and the operator can be read as an std::string using the std::cin object. Comparison is well-defined between std::string instances, so you are safe to do so.
You need not set precision for the floating point (in)equality operators. The default precision for a double
is all that is required.
You must provide operators:
<
<=
==
>=
>
! =
Points:
compilation: 1
style: 1
correctness: 2
Cont.
CSCE 240 Exam 1 Page 3 of 4
Problem 2: SumDigits
The function accepts a read-only std::string reference containing a signed integer value and returns the sum
of its digits as a string. For example, input “12345” returns “15”, i.e. 1 + 2 + 3 + 4 + 5. Negative values
should be expected, such that “-12345” returns “-15”.
Note that if you solve the problem by conversion to integers and back, the functions std::stoi and std::to string
are useful and are found in the string library already included. Usage of integer modulus by 10 (int val %
10) and integer division by 10 (int val / 10) can extract the ones-place digit and shift-right all digits to the
left of the ones-place.
A different solution would see you converting each character in the string value to an integer and summing them. You would need to handle (possible) leading signs, e.g., 12, +12, -12, etc.
Sometimes there may be errors such that strings containing something other than integers are passed in. You
should detect these errors and return the empty string (“”), e.g., 1two3, +twelve, etc. If you use std::stoi,
reference the method you used in homework program 2, if not you will need to devise your own.
Points:
compilation: 1
style: 1
correctness: 3 (non-negative, negative, error)
Cont.
CSCE 240 Exam 1 Page 4 of 4
Problem 3: File Processing
These functions accept a string file name, open the file, read the contents, and processes the contained data
as indicated (excluding the count of doubles).
The file format consists of an integer n, followed by n additional positive and negative doubles. The first
value is not part of the dataset. The values are all separated by white space and so can be parsed using
the insertion operator (>>). You should probably use the fstream object (which accepts a string in its
constructor) to read the doubles.
Functions: ˆdouble Max(const string&):
Accepts string parameter as file name, returns double value representing the largest value of the doubles
in file ˆdouble Min(const string&):
Accepts string parameter as file name, returns double value representing the smallest value of the
doubles in file ˆdouble Sum(const string&):
Accepts string parameter as file name, returns double value representing the sum of the values of the
doubles in file ˆdouble Avg(const string&):
Accepts string parameter as file name, returns floating point value representing the sum of the values
of the doubles in file ˆvoid Sort(const string&, int[]):
Accepts string parameter as file name and an double array parameter to store the values in the file pre
and post sort. The double array will be large enough to hold all double values (except count) in the file;
this is a precondition. The function stores the sorted values from the file in the double array. Notice
that this means you must use an in-place sort to sort the array. YOU MAY NOT use the algorithm
library. Any student doing so will receive 0/6 for this problem.
References:
fstream: http://cplusplus.com/reference/fstream/
string: http://cplusplus.com/reference/string/
Points:
compilation: 1
style: 1
correctness: 4 (Max: 0.5, Min: 0.5, Sum: 0.5, Avg: 1, Sort: 1.5)
The End.