Chap 7 - algorithm design & problem sloving

Question 1

stages of program development life cycle & what they mean

Answer 1

-analysis - process of investigation to find a solution to the program; uses defragmentation & abstraction
-design - doc with tasks required for solution; uses structured charts, flowcharts, pseudocode
-coding - writing programs required
-testing - text the completed program to make sure it works under all conditions
-maintenance

Question 2

what is decomposition

Answer 2

breaking down a problem into more manageable parts; decompose a computer system into its inputs, process, outputs & storage

Question 3

what is abstraction

Answer 3

simplifying a problem by focusing on essential details than the unnecessary details

Question 4

structure diagrams

Answer 4

shows hierarchy of sub systems

Question 4

flow charts

Answer 4

-shows the algorithm
has symbols to learn

Question 5

pseudocode

Answer 5

-simple method of showing an algorithm

Question 6

validation

Answer 6

ensure only reasonable data is accepted

Question 7

verification

Answer 7

check that data is not changed when entered

Question 8

types of verification check

Answer 8

-double entry - data entered twice & compared to ensure both are the same
-screen/ visual check - manual check that ensures data on screen is same as the form

Question 9

types of validation check

Answer 9

-range check - value is btw upper & lower values
-length check - data entered is of reasonable no. or an exact no. of char
-type check - data entered is of given type
-presence check - ensure data has been entered so the value is not left blank
-format check - char entered are conformed to a pre-defined pattern

Question 10

test data

Answer 10

-ensure algorithm works as expected with no errors
-use trace table to check

Question 11

type of test data

Answer 11

-normal - data accepted which the algorithm is expected to work with
-abnormal - data is rejected by algorithm as unsuitable
-boundary - plus, minus 1 from the extreme data
-extreme - largest & smallest values accepted

Question 12

trace table

Answer 12

-records results from each set in algorithm using text data
-identify variables
-first row is always dedicated to initialized variables
-do it slowly, 1 by 1