1 - Algorithms

Question 1

Describe an algorithm. (1)

Answer 1

A finite sequence of step-by-step instructions carried out to solve a problem.

Question 2

In a list of 8 numbers, what is the middle number? (Sorting)

Answer 2

5

Question 3

In a flow chart: describe the shapes used for Start/End, Instruction and Decison

Answer 3

Rounded rectangle, rectangle, diamond

Question 4

How is the lower bound of a bin packing algorithm found? (2)

Answer 4

Sum the terms, and divide by number of bins.
Always round up.

Question 5

What is the order of an algorithm?

Answer 5

A measure of its efficiency as a function of the size of the problem.

Question 6

An algorithm has order nlogn, and can sort 100 items in 0.3 seconds. Estimate the time needed for 100 items.

Answer 6

0.3 x (1000log(1000) / 100log(100))
= 0.3 x 15
= 4.5