1. Internal Sorting
File Sorting Part 2

2. Bubble Sort of an array Inefficient --- O ( N2 )
easy to code, hence unlikely to contain errors
Algorithm
for outerloop = 1 to N
for innerloop = 0 to N-2
if ( item[innerloop] > item[innerloop+1] )
swap item[i] and item[i+1]

3. Selection Sort of an array
Easy to code, less swapping than bubble, but still O ( N2 )
Splits the array into 2 lists:
one sorted (which slowly grows)
one unsorted (which slowly shrinks)
Algorithm
find the smallest item in unsorted list
swap smallest with start of unsorted list
sorted_size ++; and unsorted_size --;

4. animations and comparisons at
Quick Sort of an array
Very Fast O ( N log2 N )
A pain to program
Algorithm
recursively partition the array into sub-lists
sort infile outfile …… it's magic !!!
animations and comparisons at

5. Sorting a Linked List
Linked Lists are necessary when we don't know the size of the list
Sorting Operations for both arrays and linked lists
comparisons
arrays - need multiple indexes
LL - need multiple pointers
swaps
with big records, LL is easier:
just move a few pointers

6. Insertion Sort of Linked List
Oversimplified Algorithm:
While not eof
newptr = new record with data from file
temp = head
while (temp != NULL)
if (newptr->key < temp->key)
insert newptr before temp
else
temp = temp->next

7. Ordered Binary Tree Alternative to building Singly Linked List
Inserting new node is much easier
Traversal to find insertion is log2N
So, inserting N items takes N * log2 N compares 40 20 60 10 30 70