19 September, Day 7
Written Assignment #2 due
Wassn0, part A – resume due today
Sassn1 presentation given next time, Day 8
assign Wassn3
Chapter 22 – Minimum Spanning Trees
Data Structures:
Arrays
Stacks – LIFO access
practical example?
Queues – FIFO access
practical example?
Heap – dynamic structure with no specified internal organization
use pointers
List, eg Linked List
advantage: noncontiguous storage
physical order isn’t important
can easily reorder via pointers
Trees – a 1-to-n stucture
hierarchical – ex:
Graphs – a m-to-n structure
Dewdney’s terms: vertex/vertices (node)
edge
Read beginning of Chapter 22
Polynomial Time – means we have a “reasonable” algorithm for solving
the problem. In other words, as the problem input space gets “bigger”
we can still solve it in a reasonable amount of computational time.
Example: the GCD algorithm. Finding the GCD of 1740 and 90 does
not take that much more time than the GCD of 135 and 5. Yes, more
times through loop, but still P time. We’re guaranteed an answer in a
reasonable amount of time.
NP (nonpolynomial time) – as problem input space gets bigger, we’re
not guaranteed a reasonable amount of computational time. Example:
factorial. n! = n * (n-1)! 6! = 6*5*4*3*2*1 How to solve? A for loop.
But notice that time depends upon “size” of problem. Computing 100!
takes much, much longer than computing 5!
CSC 490 Course Notes and Outline, © Dr. Gary Locklair, Fall 2006
