Algorihms

Sorting algorithms

Talk about sorting, why you need to sort things and what

criteria you sort by.

What is sort?

Ordering something that you can compare, it has more of something than another thing

Why sort?

To find fast

- page in a book

- which size of a bus school to use

- when is the next birthday, which two kids have adjacent birthdays

Find Max and Min

- most favorite and least favorite toys

What can you sort?

- numbers (print)

- redness (print)

- roundness (print)

- height - sticks

- thickness - books

- brightness (print pics - star, lamp, candle)

- activity - order (print)

- happiness-(print smileys)

What can you not sort?

- Apples and oranges (or can you?)

- laughter, pinecone, plus, dream

Sorting the same things differently

transport - bike, motorcycle, car, bus, boat, airplane - wheels, num people (print)

planets - sizes, how far from the sun (print)

words - size, alphabetically

Try sorting algorithms

kids. Every one will get a number and then they'll have to sort

themselves using different algorithms:

1. Selection sort. Find the biggest number, put it first, then find

the biggest among the numbers that are left, etc.

2. Bubble sort. Switch places with your partner to make sure the

smaller number is on the one side, the bigger number is on the other

3. Bucket sort. Allocate placeholders for the numbers (buckets) and

have kids run to the number that matches the numbers they are holding

4. Insertion sort. Sort 2, then 3, then 4, the last one inserts himself in the sorted list

5. Merge sort. split by groups, sort in a small group, then merge

Time the kids sorting and compare which algorithm works faster. Discuss the advantages of parallel processing (such as bubble sort - kids can swap in parallel)