这是一篇关于C ++基础数据类型的作业代写
CSCI 1300 CS1: Starting Computing
Ashraf, Fleming, Correll, Cox, Fall 2019
Homework 2
Due: Saturday, September 14th, by 6 pm
(5 % bonus on the total score if submitted by 11:59 pm Sep. 13th)
2 components (Moodle CodeRunner attempts, and zip file) must be completed and submitted by Saturday, September 14th, 6:00 pm for your homework to receive points.
1. Objectives
● Understanding C++ data types and functions (parameter passing and return values)
● Writing and testing C++ functions
○ Understand problem description
○ Design your function:
■ come up with a step by step algorithm,
■ convert the algorithm to pseudocode
■ imagine many possible scenarios and corresponding sample runs or outputs
○ Convert the pseudocode into a program written in the C++ programming language
○ Test it in the Cloud9 IDE and submit it for grading on Moodle
2. Background
A function is a block of code which is used to perform a particular task. Depending on whether a
function is predefined or created by programmer; there are two types of function:
1. Library Function
2. User-defined Function
Library functions are the built-in functions in C++ programming. For example, C++ library provides sqrt() function to calculate the square root of a number.
Functions in C++
C++ allows programmers to define their own functions. These are called user-defined functions. Every valid C++ program has at least one function, that is, main() function. Other user-defined functions are called from the main() function, or from within other user-defined functions.
Here is the syntax for the function definition:
● return_typeisthedatatypeofthevaluethatthefunctionreturns.
● function_nameistheactualnameofthefunction.
● parameter_listreferstothetype,order,andnumberoftheparametersofafunction.
A parameter is like a placeholder. When a function is invoked, you pass a value to the
parameter. This value is referred to as actual parameter or argument.
● function_bodycontainsacollectionofstatementsthatdefinewhatthefunctiondoes.
The statements inside the function body are executed when a function is called.
When we don’t have user-defined functions, all statements are executed sequentially, one after another. When we have used defined functions, the flow of execution changes. Let’s follow in the example below.
return_type function_name(parameter_list) {
//function_body }
When a program begins running, the system calls the main() function. When control of the program reaches the sum() function inside the main()(in the example below, at line 13), it moves to function sum() and all code inside the function is executed (lines 6 and 7). After the sum() function finishes, the execution returns in the main() function and the following statement is executed (line 14).
Data Types in C++
When programming, we store the variables in our computer’s memory, but the computer needs to know what kind of data we want to store in them, since it is not going to occupy the same amount of memory to store a simple number than to store a single letter or a large number, and they are not going to be interpreted the same way. Some commonly used data types in C++ are:
1. int (for integers)
○ int myInt = 5;
2. char (for characters)
○ charmyChar=’c’;
3. float (for floating-point numbers)
○ floatmyFloat=4.4531;
4. double (for double precision floating-point numbers)
○ doublemyDouble=4.4531;
3. Submission Requirements
All three steps must be fully completed by the submission deadline for your homework to be graded.
1. Work on questions on your Cloud 9 workspace: You need to write your code on Cloud 9 workspace to solve questions and test your code on your Cloud 9 workspace before submitting it to Moodle. (Create a directory called hmwk2 and place all your file(s) for this assignment in this directory to keep your workspace organized)
2. Submit to the Moodle CodeRunner: Head over to Moodle to the link Homework 2 CodeRunner. You will find one programming quiz question for each problem in the assignment. Submit your solution for the first problem and press the Check button. You will see a report on how your solution passed the tests, and the resulting score for the first problem. You can modify your code and re-submit (press Check a gain) as many times as you need to, up until the assignment due date. Continue with the rest of the problems.
3. Submit a .zip file to Moodle: A fter you have completed all 10 questions from the Moodle assignment, zip all 10 solution files you compiled in Cloud9 (one cpp file for each problem), and submit the zip file through the Homework 2 link on Moodle.
4. Rubric
Aside from the points received from the Homework 2 CodeRunner quiz problems, your TA will look at your solution files (zipped together) as submitted through the Homework 2 link on Moodle and assign points for the following:
Style, Comments, Algorithm (10 points): Style:
● Your code should be well-styled, and we expect your code to follow some basic guidelines on whitespace, naming variables and indentation, to receive full credit. Please refer to the CSCI 1300 Style Guide on Moodle.
Comments:
● Your code should be well-commented. Use comments to explain what you are doing, especially if you have a complex section of code. These comments are intended to help other developers understand how your code works. These comments should begin with two backslashes (//) or the multi-line comments (/* … comments here… */) .
● Please also include a comment at the top of your solution with the following format:
Algorithm:
● Before each function that you define, you should include a comment that describes the inputs and outputs of your function and what algorithms you are using inside the function.
● This is an example C++ solution. Look at the code and the algorithm description for an example of what is expected.
Example 1:
// CS1300 Fall 2019
// Author: my name
// Recitation: 123 – Favorite TA
// Homework 2 – Problem # …
/* * * * * *
Algorithm: convert money from U.S. Dollars (USD) to Euros. 1. Take the value of number of dollars involved
in the transaction.
2. Current value of 1 USD is equal to 0.86 euros 3. Multiply the number of dollars got with the
* * * * * */
currency exchange rate to get Euros value 4. Return the computed Euro value
Input parameters: Amount in USD (double) Output (prints to screen): nothing Returns: Amount in Euros (double)
Example 2:
double convertUSDtoEuros(double dollars) {
double exchange_rate = 0.86; //declaration of exchange rate
double euros = dollars * exchange_rate; //conversion
return euros; //return the value in euros }
The algorithm described below does not mention in detail what the algorithm does and does not mention what value the function returns. Also, the solution is not commented. This would work properly, but would not receive full credit due to the lack of documentation.
/*
* conversion */
double convertUSDtoEuros(double dollars) {
double euros = dollars * 0.86;
return euros; }
Test Cases ( 20 points)
1. Code compiles and runs (6 points):
○ The zip file you submit to Moodle should contain 10 full programs (with a main()
function), saved as .cpp files. It is important that your programs can be compiled and run on Cloud9 with no errors. The functions included in these programs should match those submitted to the CodeRunner on Moodle.
2. Test cases (14 points):
For this week’s homework, 7 out of the 10 problems are asking you to create a function (Problems 3 and 5-10). In your Cloud9 solution file for each function, you should have 2 test
cases present in their respective main() function, for a total of 14 test cases (see the diagram on the next page). Your test cases should follow the guidelines, Writing Test Cases, posted on Moodle under Week 3.
5. Problem Set
Note: To stay on track for the week, we recommend to finish/make considerable progress on problems 1-6 by Wednesday. Students with recitation on Thursday are encouraged to come to recitation with questions and have made a start on a ll of the problems.
Problem 1 (5 points): Hello World program
The first program that we usually write in any language we’re learning is Hello, World. Your task is to write a Hello, World program just prints “Hello, World!” to the screen (the console window in Cloud9).
Here are some suggested steps:
Step 1: Open an Empty File
In Cloud9, select File -> New File. A new, blank file called Untitled1 will be opened.
Step 2: Your First Code
Starting on line 1 in Untitled1, type the following code.
Step 3: Saving Your File
Save the file: go to File -> Save As… A dialog box will open. Name it helloWorld.cpp and save it in the hmwk2 folder.
Note: make sure you save it with the .cpp extension or it will not compile correctly!
The .cpp extension on the filename tells Cloud9 that the file should be read in the C++ programming language. Once you save it, the lines in the file should be color-coded to reflect what they do in the program. This is called syntax highlighting.
Important: You should save your work frequently in Cloud9 to avoid losing your work in the event of the program crashing.
Step 4: Running Your Code
To run the program, click on the icon with the
green arrow next to the word Run. If it works, you
should see new terminal tab window open at the
bottom. The title of the tab shows the file being run
(hmwk2/ helloWorld.cpp), and inside the window you should see “Running ….” (again the name and full path of the file), and underneath it, the output of our program: “Hello, World!”
Step 5: Running Your Code from Command Line
Move to the “bash” tab (the first tab in the bottom panel). Right-click again and Clear the Buffer. Make sure you are inside the hmwk2 directory. Type:
$ g++ helloWorld.cpp -g -std=c++11
the -g option turns on debugging, which we will use later in the semester, so we should get used to it.
the -std=c++11 option makes sure that the c++ version used to run the program is c++ 11. If you don’t give this option then default version(which is usually C++98) is used.
This creates an executable called “a.out” (see figure below). You can run it by typing
$ ./a.out
Since no executable name was specified to g++, a.out is chosen by default. You can alternatively use the “-o” option to change the name :
$ g++ helloWorld.cpp -g -std=c++11 -o hello
creates an executable called “hello” (see figure below). You can run it by typing $ ./hello
Notice the output in the same: Hello, world!, followed by the return of the prompt, for new commands.
Step 6: Submit to Moodle CodeRunner
Head over to Moodle to the link Homework 2 CodeRunner. Submit your solution for the first problem and press the Check button. You will see a report on how your solution passed the tests, and the resulting score for the first problem. You can modify your code and re-submit (press Check again) as many times as you need to.
Step 7: The zip file submission
Remember that the file helloWorld.cpp will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Problem 2 (5 points): Hello Class program
Write a program that takes as input from the user the integer value of a CS course number. Then, your program should print “Hello, CS [course number] World!” to the screen. You will first need to prompt the user to enter a CS course number with a statement requesting them to “Enter a CS course number: ”. Once the user enters the course number, print the required output.
For example: If the user enters the input 1300, the output of the program should be,
Here are some suggested steps:
Step 1: Create a new file
Just like we did in Problem 1, create a file called helloClass.cpp.
Step 2: Write the program
Create a main() function, just like for Problem 1. You will need to modify the Problem 1 solution as follows:
● Create an integer variable to store the value of course number
● Prompt the user to enter a course number using the output: “Enter a CS course
number: ”
● Generate the final output as a combination of text (strings) and the value of the variable
holding the course number entered by the user. The output should match exactly the example below.
Step 3: Submit to the Moodle CodeRunner
Head over to Moodle to the link Homework 2 CodeRunner. Submit your solution for Problem 2 and press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Important: the cout formats provided for each problem are not suggestions – they MUST be followed precisely, word-for-word and including all punctuation marks, otherwise the CodeRunner will not recognize your results and you will not receive credit.
Step 4: The zip file submission
Remember that the file helloClass.cpp will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Problem 3 (5 points): classGreeting function
Write a function called classGreeting that takes a single integer parameter and prints a
greeting to the screen. If 1300 is the given argument value, the function should print:
Hello, CS 1300 World!
Specifications:
● Your function should have one i nput argument as an integer:
○ An integer parameter representing the course number
● Your function should NOT return anything.
● Your function should print the course number in the following format
○ Hello,CS****World!,where****shouldbereplacedbythevalueoftheinput argument
● Your function MUST be named c lassGreeting.
Here are some suggested steps:
Step 1: Create a new file
Just like we did in Problems 1 and 2, create a file called classGreeting.cpp.
Step 2: Write the program
Write the pre-processor directives (#include <…> and using namespace std;), followed by the main() function. Above the main() function, you need to write the code for the classGreeting function. Use the information provided above in the Specifications, a nd follow the syntax for a function definition provided in the Background section.
● Start with the return type
● Then the function name
● Then, in parenthesis, the type and name of the input parameter
Write the solution for the function body, in between the {}.
Step 3: Calling the function
After writing a function, it’s very important to check if your function is working as we expect. In the main() function, call the classGreeting function to test if it accomplishes the required output. Remember you will need to pass a value as an argument to the function.
Note: the submission requirements are to have at least 2 tests for each function. Follow the Writing Test Cases examples posted on Moodle
Your test cases should look like in the example below, where the name of the function is sayHello, and the main() function has two function calls.
void sayHello(string name)
{
cout << “Hello ” << name << endl;
}
int main()
{
// test 1
// expected output
// Hello Bob
sayHello(“Bob”); // first function call to sayHello()
// test 2
// expected output
// Hello Mary
sayHello(“Mary”); // second function call to sayHello()
}
Step 4: Submit to the Moodle CodeRunner
Head over to Moodle to the link Homework 2 CodeRunner. Go to Problem 3.
In the Answer Box, paste only your function definition, not the entire program.
Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
You must name the functions as indicated in each problem description. Importantly, the cout formats provided for each problem are not suggestions – they MUST be followed precisely, word-for-word and including all punctuation marks, otherwise the CodeRunner will not recognize your results and you will not receive credit.
If there are errors in your solution to a particular problem, a button labeled “Show differences” will appear below the table of tests after you hit “check”. This can be a very useful tool in helping you find small typos, especially in cout statements.
For example, below we hit “check” for a solution to problem 3 of this homework and have failed all the test cases despite getting the correct values. Hitting “Show differences”, we can see that a comma (,) is missing. When characters are in the expected output but not in your output they are highlighted in the “Expected” column.
On the other hand, when we include extra, unexpected characters in output they are highlighted in the “Got” column. Below we added additional exclamation points (!) to the output.
Step 5: The zip file submission
Remember that the file classGreeting.cpp will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Problem 4 (5 points): Calculating sphere volume and area
Alter the provided main() in sphereVolumeArea.cpp file (on Moodle) to print both the volume and surface area of a sphere with given radius. For a radius of 5, the output of the program should look like this:
Here are some suggested steps:
Step 1: Download sphereVolume.cpp from Moodle
You can find sphereVolumeArea.cpp, and upload it to your workspace on cloud9.
Step 2: Add new statements for the surface area calculation
Add statements to compute the surface area of a sphere, which is 4πr2 , where r is the radius.
Step 3: Submit to the Moodle CodeRunner
Head over to Moodle to the link Homework 2 CodeRunner. Submit your solution for Problem 4 and press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Step 4: The zip file submission
Remember that the file sphereVolumeArea.cpp (after your modifications) will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Problem 5 (5 points): sphereVolume function
Write a function called sphereVolume that determines the volume of a sphere with a given radius
and prints the result to the screen.
● Your function MUST be named s phereVolume
● Your function should have one i nput argument:
○ a floating point parameter representing the radius – as a double
● Your function should not return anything.
● Your function should print the calculated volume.
○ The output format should resemble that of the previous problem. For a radius of 5, the function should print: volume: 523.599
Follow the steps suggested for Problem 3. In Cloud9 the file should be called sphereVolume.cpp and it will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 5, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Problem 6 (5 points): sphereSurfaceArea function
Write a function called sphereSurfaceArea that determines the surface area of a sphere with given radius and prints the result to the screen. Hint: Recycle some of your work for Problem 5 to save some time here!
● Your function MUST be named s phereSurfaceArea
● Your function should have one i nput argument:
○ a floating point parameter representing the radius – as a double
● Your function should not return anything.
● Your function should print the calculated surface area.
○ The output format should resemble that of the previous problem. For a radius of 5, the function should print: surface area: 314.159
In Cloud9 the file should be called sphereSurfaceArea.cpp and it will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 6, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Problem 7 (10 points): convertSeconds function
Write a function convertSeconds that takes one integer input as seconds and converts it to hours, minutes and seconds. Your function can round off the seconds to the nearest whole value after conversion. Then, your function will print the time in hours, minutes and seconds to the screen, as demonstrated below. You should convert the amount of time in such a way that maximizes the whole numbers of hours and minutes.
● Your function MUST be named convertSeconds
● Your function should accept only one input value, seconds, as an integer
● Your function should not return any value
● Your function should print the string in the following format:
h hour(s) m minute(s) s second(s)
For example, given input seconds as 3671, it should print :
1 hour(s) 1 minute(s) 11 second(s)
In Cloud9 the file should be called convertSeconds.cpp and it will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 7, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Problem 8 (10 points): population function
The U.S. Census provides information about the current U.S. population as well as approximate rates of change. Using those rates and the current US population, write a function to calculate the U.S. population in exactly one year (365 days). Your function should return the result of your calculations. If you end up with a non-integer projected population, then round down to the nearest whole person.
Three rates of change are provided:
➢ There is a birth every 8 seconds
➢ There is a death every 12 seconds
➢ There is a new immigrant arriving in the US every 27 seconds
Specifications:
● Your function MUST be named p opulation
● Your function should accept only one input argument: the initial population, as an integer
● Your function should return the population value in a year – you should be able to figure out
the type of the return value.
● Your function should not print/display/output anything to the screen
For example, given an initial population of 1,000,000, your function would return 3,482,000.
In Cloud9 the file should be called population.cpp and it will be one of 10 files you need to zip
together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 8, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Problem 9 (10 points): carnot function
In thermodynamics, the Carnot efficiency is the maximum possible efficiency of a heat engine operating between two reservoirs at different temperatures. The Carnot efficiency is given as
η=1− TC TH
, where TC and TH a re the absolute temperatures at the cold and hot reservoirs, respectively. Write a function carnot that will compute the Carnot efficiency.
● The function must be named carnot.
● The function takes in two parameters, in this order:
○ the cold temperature reservoir operates ( TC ), integer value
○ the hot temperature reservoir operates ( TH ), integer value
● The function should return the Carnot efficiency as double.
In Cloud9 the file should be called carnot.cpp and it will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 9, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
Problem 10 (10 points): calculateSalary function
A field worker is paid $10 an hour. The hours of work for a day vary based on the weather for that day. On a rainy day, 5 hours of work can be achieved, 4 hours of work on a cold day and 8 hours of work on a bright sunny day.
Write a function called calculateSalary that returns the total money earned based on the number of rainy, cold and sunny days worked.
● Your
● Your
● Your
● Your
function name MUST be named c alculateSalary
function should accept 3 integer arguments in the order:
○ number of rainy days
○ number of cold days
○ number of sunny days respectively
function should return the salary earned as int function should not print anything
For example:
The worker worked 5 rainy days, 8 cold days and 19 sunny days. Then the total money earned will be calculated by (5*5 + 4*8 + 8*19) * 10 = $ 2090
In Cloud9 the file should be called calculateSalary.cpp and it will be one of 10 files you need to zip together for the Homework 2 on Moodle.
Don’t forget to head over to Moodle to the link Homework 2 CodeRunner. For Problem 10, in the Answer Box, paste only your function definition, not the entire program, just like you did for Problem 3. Press the Check button. You can modify your code and re-submit (press Check again) as many times as you need to.
6. Homework 2 checklist
Here is a checklist for submitting the assignment:
1. Complete the code Homework 2 CodeRunner
2. Submit one zip file to Homework 2. The zip file should be named, hmwk2_lastname.zip. It
should have following 10 files: ○ helloWorld.cpp
○ helloClass.cpp
○ classGreeting.cpp
○ sphereVolumeArea.cpp ○ sphereVolume.cpp
○ sphereSurfaceArea.cpp ○ convertSeconds.cpp
○ population.cpp
○ carnot.cpp
○ calculateSalary.cpp
7. Homework 2 points summary
Criteria
Pts
CodeRunner (problem 1 – 10) Style, Comments, Algorithms Test cases
Recitation attendance (week 3)*
70 10 20
-30
Total
5% early submission bonus
100 +5%
* if your attendance is not recorded, you will lose points. Make sure your attendance is recorded on Moodle.
