2008/05/12 Ð CS235

Sing, Prayer

Announcements

* Review schedule
o How is Project 2 coming?

Review

   MAPS
Show << MapMore.java >>
* Find common keys

Show << Anagrams.java >>
* Multi-map example (multiple values per key)
* What is an anagram? a word or phrase spelled by rearranging the letters of another word or phrase (e.g., steal, stale, and slate)
* Input:  Dictionary.txt

Show << MultiMap.java .>>

STACK

<< StackBasics.java >>
<< Balanced.java >>

QUEUE

<< Show Countdown.java >>
<< Show PCountdown.java >>


Group Work


Lecture

      Recursion Ð follow notes



GROUP WORK
5/12/2008

1. Write a non-recursive program that computes the factorial of a number n.






2. Write a non-recursive program that takes two integers, x and n, as inputs and computes x to the power of n





3. What is recursion?




4. Write the same two programs above using recursion:















Recursion Tips:
* A recursive method must have a base case
* Recursive calls generally progress towards a base case
* Assume that the recursive call works
* Never solve the same problem instance more than once