1. What is an Algorithm?
TechNights
October 17, 2016

2. An Algorithm Is…
A step-by-step set of instructions for a specific task
Clear and organized
What algorithms do you know about?

3. Lego Construction Algorithm
Teams of four
Look at the picture and build the object
Write directions on the paper (an algorithm!)
Trade pieces and directions with another team
Follow the directions to build the object—2 minutes!
Compare with the picture
A total of 5 minutes for this exercise.

4. Lego Construction Algorithm
Can we do better?
Give them 10 minutes

5. Problem-Solving Strategies
Our Toolbox
Problem-Solving Strategies

6. “Brute Force”

7. How would you find the piece that fits?
Jigsaw – each girl should have one piece
Give them 3-4 minutes

8. “Divide and Conquer” Give everyone a number. Sort yourselves!
Recursion!

9. Sort yourselves By Birthdays!
Volunteers – choose a girl to be a pivot for a couple groups
Remember Quicksort?

10. Bisection How do we search effectively?
We run a binary search on the girls
Whose birthday is closest to today?

11. Bisection

12. Bisection

13. Bisection

14. Bisection

15. “Greedy” Knapsack Problem

16. Limit: 20 pounds A. $1, 3 pounds B. $9, 4 pounds C. $5, 2 pounds
D. $9, 6 pounds
E. $11, 7 pounds
F. $6, 3 pounds
G. $12, 5 pounds
1. Choose the best item
2. If it fits, put it in and
go to step 1
3. If it doesn’t, put it aside
and go to step 1
4. If there are no more
items, stop
5. If your bag is full, stop
6. Otherwise, go to step 1

17. Choose the most ‘dense’
1. Choose the best item
2. If it fits, put it in and
go to step 1
3. If it doesn’t, put it aside
and go to step 1
4. If there are no more
items, stop
5. If your bag is full, stop
6. Otherwise, go to step 1
A. $1, 3 pounds = 0.33
B. $9, 4 pounds = 2.25
C. $5, 2 pounds = 2.5
D. $9, 6 pounds = 1.5
E. $11, 7 pounds = 1.6
F. $6, 3 pounds = 2
G. $12, 5 pounds = 2.4
Answer they should get: $50
Also the optimal answer

18. How do I write a clear algorithm? What strategies can I use?
Reflection
How do I write a clear algorithm?
What strategies can I use?