1. Spring 2010
EECS 110: Homework I

2. Homework I Problems Extra Problems Rock-Paper-Scissors (fair game)
Functions Frenzy
Extra Problems
Pig Latin
Scoring Paper

3. Problem 3: Rock, Paper, Scissors Overview
Objective: Play rock-paper-scissors fairly
Steps for the program:
Choose the computer choice randomly (without revealing this value to the user)
Ask the user for their choice (give warning for incorrect choice)
Figure out the winner & print out the result

4. Problem 3: Rock, Paper, Scissors Random choice
Using choice function from random package
Example code: from random import * s = choice(['thread','yarn','twine']) print 'I chose', s

5. Problem 3: Rock, Paper, Scissors A while loop
Execute a block of code repeatedly as long as a condition is satisfied.
Application: Keep asking as long as incorrect choice is given by the user
Example code: answer = 'no' while answer == 'no': [body of the program] answer = raw_input('Want to stop? ')

6. Problem 4: Recursive Functions Overview
Problems:
Multiplication: mult(n,m)
Dot product: dot(L,K)
First index: ind(e,L)
Scoring Letter*: letterScore(let)
Scoring Word: scrabbleScore(S)
Recursive Functions:
Base case
Recursive part

7. Problem 4: Recursive Functions Multiplication
Return: product of 2 integers
Requirements:
Use recursion
Use only: addition, subtraction, negation
Hints:
Use the construction of function power as a guide
m * n = m added together n times
Handling negative numbers

8. Problem 4: Recursive Functions Dot Product
Return: dot product of any 2 lists
Return 0.0 when
Lists have unequal lengths
Empty lists
Hints:
Use the construction of function mysum as a guide
Dot product = sum of products of elements in the same position
Example: [5,3] o [6,4] = 5*6 + 3*4 = 42

9. Problem 4: Recursive Functions First Index
Return: first index of an element in a list
Requirements
Use Recursion
Counting starts at 0
Nonexistence = return any integer ≥ len(L)
Examples: >>> ind(42, [55,77,42,12,42,100])‏ 2 >>> ind('i', 'team')‏ 4

10. Problem 4: Recursive Functions Scoring Letter
Return: score of a letter based on
Requirements
No recursion needed
Return 0 for input that is not from 'a' to 'z'
Hints:
Use in keyword: >>> 'a' in 'this is a string with letter a' True

11. Problem 4: Recursive Functions Scoring Word
Return: score of a string
Requirements
Use recursion
Hints:
Use the construction of function mylen as a guide
Use letterScore(let) as previously defined

12. Extra Credit 1: Pig Latin Overview
The warm-up: pigLatin(s)
The challenge: spamLatin(s)

13. Extra Credit 1: Pig Latin The Warm-up pigLatin(s)
Input: single word, lower letter string s
Translate to Pig Latin based on these rules
If s is an empty string:
return an empty string
If s begins with a vowel (a,e,i,o,u)
Append 'way' to the end of s
Example: pigLatin('one') returns 'oneway'
If s begins with a consonant (the rest including y)
Move this consonant to the end
Then append 'ay' to the end
Example: pigLatin('be') returns 'ebay'

14. Extra Credit 1: Pig Latin The Challenge spamLatin(s)
Input: single word, lower letter string s
Translate to Pig Latin based on these rules
If s is an empty string, or begins with a vowel, same with pigLatin(s)
If s begins with a consonant
Move all initial consonants to the end
Then append 'ay' to the end
Example: pigLatin('string') returns 'ingstray'

15. Extra Credit 1: Pig Latin The Challenge spamLatin(s)
Rules (continue)
If s starts with 'y' which is followed by
a vowel, then consider this 'y' to be a consonant
a consonant, then consider this 'y' to be a vowel
spamLatin('yttrium') returns 'yttriumway'
spamLatin('yoohoo') returns 'oohooyay‘
Other cases: free to decide

16. Extra Credit 2: Scoring File Overview
Input: a file name
Output:
Total Scrabble score
Total number of alphabetic characters
Average Scrabble-score-per-letter
Important: both upper- and lower-case letters

17. Extra Credit 2: Scoring File Reading a File
def printFileToScreen(fileName): f = file(fileName) text = f.read() f.close()
print 'The file contains:' print print text

18. Extra Credit 2: Scoring File Large Recursive Call
Recursive stack is limited at 1000 calls by default
Change this temporarily: import sys sys.setrecursionlimit(100000)‏

19. Extra Credit 2: Scoring File Testing
Test on 2 additional files
Convert your files to plain text first
Include the results at the top of your program

20. Last points Name your files correctly
Include docstring for your functions
Test thoroughly
Good luck