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  1. Read the sections of Visual Layout, Comments, and Naming in the programming style guide and tips.
    Warning!

    Points will be deducted if you violate the the programming style guide!

    • Your code should have good indentations and line breaks.
    • Give appropriate comments to your code.
    • Your variable names should be chosen well.
  2. (10 pts) We would like you to self-test how much you retained from the lecture. Write the correct solution to the Practice Problem of "Roots of Quadratic Polynomials" -- debug your code until it runs correctly. Circle below how you wrote your code.
    1. (10 pts) I was able to write the code without referring to anything.
    2. (10 pts) I had to look at the notes, but still I was able to write the code without looking at the solution.
    3. (10 pts) I had to look at solutions to finish to code.
    4. (0 pts) I didn't do this.
    If you had to look at the solution, briefly describe what you missed but understand now.
  3. (70pts) Consider the following diagram with a large right triangle containing a small right triangle:

     

    The length of AC is \(\sqrt{x^2-y^2}\). The length of BD is \(\sqrt{|DC|^2+y^2}\), where \(|DC|\) is the length of DC.

    You are to write a program that works as follows:

    • The program gets lengths x, y and z from the user
    • Then, it computes the length of the dashed line segment BD.
    • Your file must be named hw.cpp. You may assume that the user inputs valid data.
    • Your output must be in exactly the form shown in the examples below.

    The red text in the below examples is user input.

    Example 1

    $ ./a.out
Enter length x: 3.5
Enter length y (<3.5): 1.8
Enter length z (<3.00167): 2.1
Length of BD is 2.01321

    Example 2

    $ ./a.out
Enter length x: 5.1
Enter length y (<5.1): 4.8
Enter length z (<1.72337): 1.5
Length of BD is 4.80519

    Example 3

    $ ./a.out
Enter length x: 3.5
Enter length y (<3.5): 1.8
Enter length z (<3.00167): 0.25
Length of BD is 3.28811

    To explain the conditions for y and z in the above, because we have a triangle,

    Hint: A great way to write a program is to get a little bit working, compile and debug, then get a little more work, compile and debug, etc. So you might start trying to get something like this working:

    $ ./a.out
Enter length x: 5.1
Enter length y (<5.1):

    Once you've tested and debugged that, try and extend it so that the following works:

    $ ./a.out
Enter length x: 5.1
Enter length y (<5.1): 4.8
Enter length z (<1.72337):

    Once that works, you can try to finish the whole thing off.

  4. (4 pts) What's the output of the following code snippet? 
    
cout << 3/4 << endl;
cout << 20 % 7 << endl;
  5. (10 pts) What is the type of each of the following values? 
     -0      0.0     '0'    "-0.0"       false
  6. (8 pts) Fill out the table
    CodeUser InputProgram OutputUnread Input
    char c;
cin >> c;
cout << c << endl;
    		 103.07% 1.2% 
    int k;
cin >> k;
cout << k << endl;
    		 103.07% 1.2% 
    double x;
cin >> x;
cout << x << endl;
    		 103.07% 1.2% 
    string s;
cin >> s;
cout << s << endl;
    		 103.07% 1.2%

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