1. Classification of Algorithms
Kasun Ranga Wijeweera
(Email: krw19870829@gmail.com)

2. Background
• N = Primary Parameter
• N might be
 The degree of a polynomial
 The size of a file to be sorted or searched
 The number of nodes in a graph, etc

3. 1 CONSTANT
• Most instructions of most programs are executed once or at
most only a few times
• If all the instructions of a program have this property, we say
that its running time is constant

4. Log N LOGARITHMIC
• This running time commonly occurs in programs that solve a
big problem by transforming it into a smaller problem, cutting
the size by some constant fraction

5. N LINEAR
• It is generally the case that a small amount of processing is
done on each input element

6. N Log N LINE ARITHMIC
• This running time arises for problems that solve a problem by
breaking it up into smaller sub problems, solving them
independently, and then combining the solutions

7. N2 QUADRATIC
• These problems arise in algorithms that process all pairs of
data item
• Example: Perhaps in a double nested loop

8. N3 CUBIC
• These problems arise in algorithms that process triples of data
items
• Example: Perhaps in a triple nested loop

9. 2N EXPONENTIAL
• These problems arise naturally as “brute force” solutions to
problems

10. Reference

11. Any Questions?

12. Thank You!