Description
Overview
This lab will give you some insight of the power associated with Object Oriented
Programming by exploring the concept of structures. In addition, you will have to perform simple string operations, which are essential tools for programmers dealing with text. As will become clear in this lab, structures allow programmers to define their own “data type” by defining objects. In this lab, you will define a Time structure that represents hours, minutes, and seconds of the day, along with a Course structure that represents a course that you can take at a University. Together, the structures can be used to create a schedule of course for students.
Note: You need to have a separate program for each part of this lab. When you submit your assignment through CatCourses, make sure that ALL PARTS are included.
Getting started
Create a new directory in your main development directory (probably on Desktop/CSE30) called Lab_06. Try to use the terminal on your own, without getting help from the TA to setup the new directories (try to learn/remember the terminal commands).
Reminder: Once you have created a file and understood its content, you want to compile the source file (ex. main.cpp) into an executable so that you can run it on your computer. Note: EVERYTIME you modify your source file, you MUST re-compile your source file for the changes to take effect. You will compile from the command line by running:
g++ <source> -o <executable>
where g++ is a program (already installed on your Linux system) that compiles C++ source files, source is the source file for your program (main.cpp in this example), -o tells the compiler that you want to give the executable its own name, and executable is the name you want to give your program. In order to compile your first program, you would have to run:
g++ main.cpp -o main
Assuming that your program compiled successfully (i.e. no errors were found), you can run your program by typing “./main” in the terminal/console.
Good coding practices (worth 2 points!)
Writing code that is understandable by humans is as important as being correct for compilers. Writing good code will help you complete the code, debug it and … get good grades. It is very important to learn as soon as possible, because bad habits are hard to get rid of and good habits become effortless. Someone (guess who) reads your code will be in a better mood if it is easy to understand … leading to better grades! This lab will include 2 points (10% for code quality):
- Explanations with comments
- Meaningful names
- Indenting of blocks { } and nesting …
- Proper use of spaces, parentheses, etc. to
- Visible, clear logic
- One / simple statements per line
- Anything that keeps your style consistent
(Exercise 1) Create – timeInput.cpp
In this part of the lab, you will be creating your own Time structure to keep track of various times of the day. Your Time structure should contain 3 integer variables:
- one for the hour
- one for the minutes
- one for the seconds
Your program will setup a start & end time for a lecture at the University. It will ask the user to enter the start time and the end time for the lecture, using the 24 hour format (HH:MM:SS). You need to check that the input produces a valid time:
- check if the string contains the right characters (i.e. two characters [0-9], a colon, etc.)
- check if the time entered makes sense (i.e. HR is 0-23, etc. … for instance, 33:79:99 does NOT make sense).
- If the time is incorrect, output an error message and exit the program.
Once the user has entered two valid times, your program will output the start and end times in a 24 hour format. For those who are unfamiliar with 24 hour format, please see http://en.wikipedia.org/wiki/12-hour_clock.
Note: in order to receive full credit for this part of the lab, you MUST create a main program that defined the Time structure and the following two functions:
- getTimeFromUser: takes in a Time structure variable as a parameter, reads a string from user, checks to see if it is a valid 24 hour format, stores it inside the Time structure variable, and return true or false depending on whether or not the time is valid. Since the Time structure is not returned at the end of this function, you need to pass the reference (&) of the Time structure instead of the identifier (name) as the parameter. This way, the contents of the Time structure will be updated after the function is executed and goes back to the main function.
o Write a pseudocode of getTimeFromUser function before writing it in C++ code.
- print24Hour: takes in a Time structure variable as a parameter and prints the time using the 24 hour format.
Hints:
- see the following examples for the output structure
- use getline with cin for all of the user input e. getline(cin, my_line) instead of cin >> my_line in order to read symbols (“:”) from user.
- you will need to read the entire string for the time (i.e. 12:30:00), and process it to extract the numbers. You should extract the numbers one by one, convert them to integers, and store them in your structure. The string functions substr and find will be especially useful.
- substr(x, n) will return a string of n characters starting at position x of my_line. Find more information about substr function at http://www.cplusplus.com/reference/string/string/substr/
- find(“ABC”, x) will search for “ABC” starting at the position x of my_line and return the position of the first occurrence of “ABC” (at or after position x). Find more information about find function at http://www.cplusplus.com/reference/string/string/find/
- as you have done in previous labs, you will need to convert from strings to integers. The function you can use to do so is atoi, which takes in an array of characters as a parameter (NOT a string). To convert a string to an array of characters, use the function c_str(). e. atoi(my_line.c_str())
- in some cases, you will need to add a 0 in front of single-digit numbers (e.g. 15:02:00, as opposed to 15:2:0). The functions setw and setfill will allow you to do that.
- cout << setfill (‘x’) << setw (10); will set ‘x’ to fill up 10 character spaces. o cout << 77 << endl; will output xxxxxxxx77 when the previous line was used.
- Find more information about setfill and setw functions at http://www.cplusplus.com/reference/iomanip/setfill/
Example 1:
Enter the start time for the lecture (format is HH:MM:SS): 12:22PM The start time entered is invalid!
Example 2:
Enter the start time for the lecture (format is HH:MM:SS): 23:59:59 Enter the end time for the lecture (format is HH:MM:SS): 23:85:00 The end time entered is invalid!
Example 3:
Enter the start time for the lecture (format is HH:MM:SS): 09:00:00
Enter the end time for the lecture (format is HH:MM:SS): 10:15:00
The lecture starts at 09:00:00 and ends at 10:15:00
Example 4:
Enter the start time for the lecture (format is HH:MM:SS): 13:00:00
Enter the end time for the lecture (format is HH:MM:SS): 13:15:30
The lecture starts at 13:00:00 and ends at 13:15:30
(Exercise 2) Create – courseInfo.cpp
In this exercise you will expand your timeInput.cpp, which only deals with lecture times, so that you can have more information about each lecture, and print a schedule to the student. More specifically, you should keep your Time structure from timeInput.cpp and create a new Course structure consisted of the following variables:
- name, type string, which stores the name of the course
- credits, type int, which stores the number of credits for the course
- majorRequirement, type bool, which tells if the course is a requirement for your major
- avgGrade, type double, which gives the average grade (in percentage) that past students received in the course
- days, type string, which stores the days that lectures are held
- startTime, type Time (from exercise 1), which is the start time of the lecture
- endTime, type Time (from exercise 1), which is the end time of the lecture
Your program should read the course information from a text file called “in.txt”. This file should contain the following pieces of information on the lines specified below:
Line 1: Course number: How many courses the user wants to sign up for.
Line 2: Name of the course
Line 3: Credits
Line 4: Is the course a major requirement? (1=yes, 0=no)
Line 5: Average grade for the course
Line 6: Lecture days
Line 7: Start time of the lecture
Line 8: End time of the lecture
Line 9-15: Repeat same information for additional course, if it exists.
Note:
- In order to receive full credit for this part of the lab, you MUST create the two structures, Time and Course, consisted of the proper variables.
- In order to read the avgGrade, you will need to convert from strings to floats. The function you can use to do so is atof, which takes in an array of characters as a parameter (again, NOT a string). To convert a string to an array of characters, use the function c_str().
Example 1: in.txt:
1 cse20
4
1
89
Mondays
16:30:00
17:20:00
Your output should be:
−−−−−−−−−−−−−−−−−−−
SCHEDULE OF STUDENT
−−−−−−−−−−−−−−−−−−−
COURSE 1: cse20
Note: this course is a major requirement!
Number of Credits: 4
Days of Lectures: Mondays
Lecture Time: 4:30:00pm -5:20:00pm
Stat: on average students get 89% in this course.
−−−−−−−−−−−−−−−−−−−
Example 2: in.txt:
3 cse20
2
0
75
Mondays
16:30:00 17:20:00 cse30
4
1
78
Mondays and Wednesdays
16:30:00 17:45:00 math5
3
0
98
Tuesdays
09:00:00
09:50:00
Your output should be:
−−−−−−−−−−−−−−−−−−−
SCHEDULE OF STUDENT
−−−−−−−−−−−−−−−−−−−
COURSE 1: cse20
Note: this course is not a major requirement…
Number of Credits: 2
Days of Lectures: Mondays
Lecture Time: 4:30:00pm -5:20:00pm
Stat: on average students get 75% in this course.
−−−−−−−−−−−−−−−−−−−
COURSE 2: cse30
Note: this course is a major requirement!
Number of Credits: 4
Days of Lectures: Mondays and Wednesdays Lecture Time: 4:30:00pm -5:45:00pm
Stat: on average students get 78% in this course.
−−−−−−−−−−−−−−−−−−−
COURSE 3: math5
Note: this course is not a major requirement…
Number of Credits: 3
Days of Lectures: Tuesdays
Lecture Time: 9:00:00am -9:50:00am
Stat: on average students get 98% in this course.
−−−−−−−−−−−−−−−−−−−
Example 3: in.txt:
0 Your output should be:
−−−−−−−−−−−−−−−−−−−
SCHEDULE OF STUDENT
−−−−−−−−−−−−−−−−−−−
