2. Functions

  • Feel free to use your laptop

  • You are strongly encourage to work with others

    • When you get stuck, ask those sitting around you for help

    • Get used to working together in the labs

    • Peer teaching and peer learning has been empirically shown to be very effective

2.1. Pre Lab Exercises

  1. Chapter 2 exercise(s)

    • 5 but have it in a function that returns the result

  2. Chapter 4 exercise(s)

    • 8

2.2. Before Kattis

  1. Write a function called add_five_print(some_integer)

    • The code you write must be within a function

    • The function will take one parameter some_integer

    • The function adds five to the parameter and prints out the result

    • The function will not return anything

    • Call the function a few times to verify that it works properly

    1def add_five_print(some_integer):
2    # stuff goes here

  2. Write a function called add_two_numbers_print(some_integer, some_other_integer)

    • The code you write must be within a function

    • The function will take two parameters some_integer and some_other_integer

    • The function will calculate their sum and print out the result

    • The function will not return anything

    • Call the function a few times to verify that it works properly

    1def add_two_numbers_print(some_integer, some_other_integer):
2    # stuff goes here

  3. Write a function called add_two_numbers_return(some_integer, some_other_integer)

    • The code you write must be within a function

    • The function will take two parameters some_integer and some_other_integer

    • The function will calculate their sum

    • The function will return the result

    • Call the function a few times to verify that it works properly

  4. Run the following code and take note of the output

    1result = add_two_numbers_return(4, 5)
2print(result)

  5. Run the following code and take note of the output

    1result = add_two_numbers_print(4, 5)
2print(result)

  6. Why do these two functions behave differently when called?

    • Take note of when and where print is called

  7. Write a function called this_is_tough(n1, n2, n3, n4)

    • The code you write must be within a function

    • This function will take four parameters n1, n2, n3, and n4

    • This function will sum all four numbers

    • The function will return the result

    • You can not make use of the addition operator (+) directly within this function

    • You must make use of add_two_numbers_return three times

    • Verify correctness by running the function a few times

2.3. Kattis Problems

  • Do not forget the code we used last time to read input on Kattis

1data = input()       # Read a WHOLE, SINGLE line of input
2data = data.split()  # Split string into individual pieces
3a_var = int(data[0]) # Take string from data[X], convert it to int...
4b_var = int(data[1]) # ... And store it in some variable

Warning

The above code will only work when the input is 2 integers on the same line. You may need to hack this code to make it work for your particular problem.

  • Skip any of the following problems if you did them already.

  1. https://open.kattis.com/problems/hello

  2. https://open.kattis.com/problems/carrots

  3. https://open.kattis.com/problems/r2

  4. https://open.kattis.com/problems/faktor

  5. https://open.kattis.com/problems/ladder

  6. https://open.kattis.com/problems/planina

  7. https://open.kattis.com/problems/leggjasaman

  8. https://open.kattis.com/problems/metronome

  9. https://open.kattis.com/problems/ovissa

  10. https://open.kattis.com/problems/fifa

  11. https://open.kattis.com/problems/vidsnuningur