CSC111 Homework 2 2015b

--D. Thiebaut (talk) 18:20, 15 September 2015 (EDT)

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This homework is due on Tuesday 9/22 at 11:55 p.m.

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Problem 1

Write a program called hw2_1.py that displays a table of temperatures, the left column in Fahrenheit, and the right column in Celsius. The program asks the user for two numbers, a temperature T, and a number of temperatures n, and displays a conversion table showing n lines of temperature conversions.

Here is an example of how your program should work (the user input is in boldface):

Please enter the starting temperature:  30
How many lines do you want for the table?  10

Fahrenheit Celsius
30         -1.11111111111
31         -0.555555555556
32         0.0
33         0.555555555556
34         1.11111111111
35         1.66666666667
36         2.22222222222
37         2.77777777778
38         3.33333333333
39         3.88888888889

And here is another example:

Please enter the starting temperature:  32
How many lines do you want for the table?  4
 
Fahrenheit Celsius
32         0.0
33         0.555555555556
34         1.11111111111
35         1.66666666667

• Make sure to label the columns with " Fahrenheit" and "Celsius" please!
• Make sure to leave a blank line between the input part of your program's output (the prompt for the two temperatures), and the real output. This blank line is expected by the automatic grader.
• Submit your program on Moodle, in the HW2 PB1 section.

Problem 2

Write a program called hw2_2.py that displays a table of temperatures, the right column in Celsius, and the left column in Fahrenheit. The program asks the user for three numbers:

• a temperature T,
• a number of temperatures n,
• and the step used to skip temperatures.

If the user enters 1 for the step, the output of this program will be the same as the output of the solution program for Problem 1.

Note: we assume that the step will always be positive.

Here is an example of how your program should work (the user input is in boldface):

Please enter the starting temperature:  30
How many lines do you want for the table?  5
What step should be used? 2 

30         -1.11111111111
32         0.0
34         1.11111111111
36         2.22222222222
38         3.33333333333

And here is another example:

Please enter the starting temperature:  32
How many lines do you want for the table?  3
What step should be used? 2 
 
32         0.0
34         1.11111111111
36         2.22222222222

• Submit your program on Moodle, in the HW2 PB2 section.

Problem 3

This problem is the same as Problem 1, except that the output now shows degrees Kelvin, as well. A degree Kelvin is computed as degrees celsius + 273.15.

For example, if you have a variable called celsius that contains the temperature expressed in Celsius, and you want to compute the equivalent Kelvin temperature, and store that value in a variable called kelvin, you would write:

      kelvin = celsius + 273.15

Here is an example of how your program should behave:

Enter low temperature: 30
How many lines? 5

Fahrenheit Celsius Kelvin
30         -1.11111111111 272.038888889
31         -0.555555555556 272.594444444
32         0.0 273.15
33         0.555555555556 273.705555556
34         1.11111111111 274.261111111

Do not worry about the unpleasantly formatted output. Right now your job is to concentrate on the loop construct. We'll see how to format real numbers later!
Submit your program to the HW2 PB3 section on Moodle.

Problem 4

This problem is the same as Problem 3, except that the output now shows degrees Kelvin listed first on a line, then Celsius, then Fahrenheit.

Here is an example of how your program should behave:

Enter low temperature in Fahrenheit: 30
How many lines? 6

Kelvin Celsius Fahrenheit
272.038888889 -1.11111111111 30
272.594444444 -0.555555555556 31
273.15 0.0 32
273.705555556 0.555555555556 33
274.261111111 1.11111111111 34
274.816666667 1.66666666667 35 

Submit your program to the HW2 PB4 section on Moodle.

Problem 5: Loops and Triangles

Preparation

Using the Python Shell window, type the following statements one after the other, and try to figure out what is going on:

>>> line = "!"

>>> line

>>> line = 5 * "!"

>>> line 

>>> line = 20 * "a"

>>> line

>>> n = 7

>>> line = n * "b"

>>> line

Using this information, write a new program that uses one for-loop to display the following triangle:

*
**
***
****
*****

Every time your program runs, it just displays the same pattern: five lines. First line with one star, last line with five stars (Hints: use a loop that goes from 1 to 5!)

When this test program works well, modify it so that it first asks the user how many lines the triangle should have, and then the program displays a triangle with that number of lines.

Here's an example of how your program should work (the user input is underlined):

How many lines? 7

* 
**
***
****
*****
******
*******

Here's another example:

How many lines? 2

* 
**

When your program works well, you are ready to write the program you need to submit.

Your Assignment

Write a new program that will prompt the user for a number and use this number to print two triangles made of stars on the screen. The number entered by the user will define the number of lines used to display the triangles.

Here is an example of how the program will work when the user enters 5:

How many lines? 5
 
triangle 1

*
**
***
****
***** 

triangle 2

*****
****
***
**
*

Note that all the triangles are flush against the left margin.

Submit your program to the HW2 PB5 section on Moodle.
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Solution Program

# hw2.py
# D. Thiebaut
# This program contains the solution programs for Homework 2.
# The different solutions are stored in separate functions.  Do not
# worry about using functions.  You didn't have to use functions
# for this assignment.  All you have to do is look at the code inside
# a function to see what you were supposed to do.

# This is a solution for Lab 2
def prompt1():
    fname = input( "your first name?   " )
    lname = input( "your last name?    " )
    box   = input( "your box number?   " )
    phone = input( "your phone number? " )
    Id    = input( "your Id number?    " )

    print( "+---------------------------------" )
    print( "| Name:  ", fname, lname, "(", Id, ")" )
    print( "| Box    ", box )
    print( "| Phone: ", phone )
    print( "+---------------------------------" )

# another solution for Lab 2
def prompt2():
    temp1 = eval( input( "Enter low temperature: " ) )
    temp2 = eval( input( "Enter high temperature: " ) )
    print()
    print( "Fahrenheit Celsius" )
    for temp in range( temp1, temp2+1 ):
        print( temp, "       ", (temp-32)*5/9 )

# Solution for Problem 1
# The code asks the user for 2 numbers and displays a table
# of temperatures in Fahrenheit and Celsius
def hw2_1():
    temp1 = eval( input( "Enter low temperature: " ) )
    noLines = eval( input( "How many lines? " ) )
    print()
    print( "Fahrenheit Celsius" )
    for temp in range( temp1, temp1 + noLines ):
        print( temp, "       ", (temp-32)*5/9 )
    
# Solution for Problem 2
# The code asks the user for 3 numbers and displays a table
# of temperatures in Fahrenheit and Celsius.
# The 3 numbers are the starting temperature, the number
# of lines, and the step between Fahrenheit temperatures.
def hw2_2():
    temp1 = eval( input( "Enter low temperature: " ) )
    noLines = eval( input( "How many lines? " ) )
    step = eval( input( "Step? " ) ) 
    print()
    print( "Fahrenheit Celsius" )
    for temp in range( temp1, temp1 + step*noLines, step ):
        print( temp, "       ", (temp-32)*5/9 )
    
# Solution for Problem 3.  The program asks for 2 numbers
# and displays a table of temperatures, with Fahrenheit, 
# Celsius and Kelvin
def hw2_3():
    temp1 = eval( input( "Enter low temperature: " ) )
    noLines = eval( input( "How many lines? " ) )
    print()
    print( "Fahrenheit Celsius Kelvin" )

    # display the table
    for temp in range( temp1, temp1 + noLines ):
        celsius = (temp-32)*5/9
        kelvin = celsius + 273.15
        print( temp, "       ", celsius,  kelvin )

# Solution for Problem 4.  The program asks for 2 numbers
# and displays a table of temperatures, with Kelvin,
# Celsius and Fahrenheit.  
def hw2_4():
    temp1 = eval( input( "Enter low temperature: " ) )
    noLines = eval( input( "How many lines? " ) )
    print()

    # display the table
    print( "Kelvin Celsius Fahrenheit" )
    for temp in range( temp1, temp1 + noLines ):
        celsius = (temp-32)*5/9
        kelvin = celsius + 273.15
        print( kelvin, celsius, temp )

# Solution for Problem 5
# Asks the user for a number of lines of stars
# and displays 2 triangles, one with the tip at the top
# and the second one with the tip at the bottom.
def hw2_5():
    noStars = eval( input( "How many lines of stars? " ) )
    print()
     
    # display first trianble
    print( "triangle 1" )
    print()
    for n in range( 1, noStars+1 ):
        print( n * '*' )
    print()

    # display second trianble
    print( "triangle 2" )
    print()
    for n in range( noStars, 0, -1 ):
        print( n * '*' )
    print()
    
# --------------------------------------------------------------------
# uncomment the line below that corresponds 
# to the solution you want to run
# --------------------------------------------------------------------
#hw2_1()
#hw2_2()
#hw2_3()
#hw2_4()
hw2_5()

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