problem solving Flashcards
Problem Solving
Problem Solving is the process of creating a set of instructions that when executed accepts
input and produces meaningful information.
Algorithm
An algorithm is a sequence of instructions which rigorously defines a solution to a problem.
Steps to Problem Solving
- Define the Problem
- Propose and evaluate solutions
- Determine the best solutions
- Develop the algorithm
- Represent the algorithm as pseudocode or flowchart
- Test and validate the solution.
Divide and Conquer Approach
to repeatedly spilt a large roblem into a number of smaller sub-problems until a complete solution is identified.
IPO CHART
is a helpful diagrammtic way to strart. it has three cateogries
Input
Processing
Output
what is a loop
A loop occurs when a statement or statements are repeated until a condition is met.
name the two types of loops
There are two types of loops:-
Definite or Bounded Loop – these are loops where you know in advance how many times to
repeat the loop ( a fixed number of times) e.g. FOR loop
Indefinite or Unbounded Loop – these are loops where you do not know in advance how
many times to repeat the loop e.g. WHILE or REPEAT loops
what is a repeat loop?
The REPEAT construct repeatedly executes one or more statements as long as a condition is
met. This condition is tested at the end of the loop so the statement will always be executed at
least once.
3 types of control structures
Sequential statements – every line of the algorithm is carried out in the order
in which it was written.
Selection or Conditional statements – not every line of the algorithm may be
carried out (IF THEN ELSE). The line of code would be carried out based on a
condition.
Repetition or Loop or Iteration – some lines of the algorithm may be repeated
until a condition is satisfied.
what is a control structure
A Conditional statement allows decisions to be made in a program
i.e. it decides which statements are to be executed or carried out
if then statements
The IF THEN statement is used when ONE option is given based on a condition
if then else statements
The IF THEN ELSE statements are used when TWO options are given based on a condition
what is a variable
A variable is an area of storage whose value can change during processing. E.g. price
what is a constant
A constant is an area of storage whose value cannot be changed during processing. E.g pi is always
3.14
what is an identifier
An Identifier is the name given to a variable or constant by a programmer.
what is an algorithm
An algorithm is a set of instructions that if followed in sequence will lead to a solution for the problem.
All algorithms share these basic characteristics:
It must have a finite number of steps OR it must end.
It must be precise
It must be unambiguous
It must be in a logical sequence.
what is a data type
A data type specifies what sort of values a variable or constant can hold.
types of data types
Integer- Whole numbers (positive and negative) e.g. 0, 5, -50
Real- Any number that contains decimal places (positive and negative) e.g.
0.2, 1.5, -50.4
String- Text or a sequence of characters e.g. ‘Frank’, ‘bus’, ‘S24’
Char- A single character found on the keyboard e.g. A, a, 5, $
Boolean- A true or false value or Yes/No
what is pseudocode
lists in words the steps to solve the problem in a
structured way.
flowcharts
a diagrammatic way to represent the algorithm.
flowchart symbols
Oval- Start/End Directional Arrow- Shows the flow of the algorithm Rectangle- Process (calculations) Parallelogram- Input/output Diamond- Selection (IF Then Else) Circle- Connector
what is a trace table
A trace table is a table used to manually trace your algorithm to
ensure that it produces the correct results.
what is a spreadsheet
An electronic spreadsheet is a program which organises
information into rows and columns so that it can be
manipulated easily. It is generally used for numerical data.
advantages of a spreadsheet
Calculations are error free
Sort and filter the entries in the worksheet.
Create graphs and charts from the data.
Insert or delete rows or columns at any position in the worksheet.
rows
these run left to right horizontally and their position is designated by a number.
coloums
these run from top to bottom vertically and their position is designated by a
letter.
cell
these are rectangle boxes formed from the intersection of a row and a column.
Each cell in the spreadsheet is identified by a cell address or cell reference
range
identifies a rectangular block of cells
worksheet
a single page in a spreadsheet file.
workbook
Contains one or more worksheets in a spreadsheet file.
labels
these refer to text in the spreadsheet.
values
this refers to numbers that can be used in a formula.
formula
this refers to numbers that can be used in a formula. starts with an = sign
functions
COUNT- Finds how many values are in a range of cells
COUNTA- Finds how many labels are in a range of cells
COUNTIF- Finds the number of values that meets a condition in a range of cells.
when is a relative address used
A relative address is used in a formula and is adjusted automatically if the formula is copied to another cell.
absolute addressing
This refers to one particular cell address and that should not be changed or adjusted when the
formula is copied to another cell using fill handle.
rank
This returns a number in relation to a list of numbers e.g the highest number in a list of
numbers would return 1.
Field description
an optional description for each field
Field Size
limits the amount of characters to a specified number in a field
or
limits a field to specified number of chararters
Format
controls the way data apears
Decimal Places
displays a set number of decimal places
Input Mask
sets a pattern that determines the format of data
Caption
specifies a label other than the field name that appears on the table
Default Value
dispalys a specified value for a field
Validation Rule
limits the data entered to meet a certain criteria
Required
specifies that a field cannot be left empty
Primary Key
Primary key refers to field that can uniquely identify with a record i.e. no two records can have the same primary key.
Relationship
A relationship occurs when two tables are joined together, for this to occur there must be a common field in both tables: in one tbale that field must be a primary key and in the other table it can be a foreign key.
Design View
Design View enables you to design and set up your database (kind of like a behind the scenes). It’s where you can set up and configure your tables, reports, forms, etc.
Datasheet View
Datasheet View is a useful way of viewing data. It allows the user to view many tables and records at the same time. The information is displayed in rows and columns– similarto a spreadsheet. A record is displayed as a row.
What is Database?
Is an organized collection of data generally stored and accessed electronically from a computer system.
Database Management (DBMS)
This is the term for any program that handles the storage, modification and retrieval of data as well as controlling who has access to the information e.g. Microsoft access
Relationship between a table, a record and a field
A table consists of a collection of records. - larges
A record consists of a number of fields (a row in a table).
A field is the smallest piece of data that can be stored.
Advantages of a Database
Saves paper and space
Update data is quick and easy
It is more secure
Data can be easily shared
Disadvantages of a Database
Expensive equipment is required computer
Pron to data corruption
Limited data storage capacity
May required specials skills and training
The purpose of a database
Data is essential to the survival of businesses.
In some organizations, data is the most valuable resource.
Data can be used as a commodity; it can be bought or sold.
Objects
components that makes up a database
Database
consists of multiple tables
Quarry
asks specific questions about data in a database
Form
a graphical user interfaces designed specifically for entering and displaying data
Report
summarize and formats the data
Text
Includes letter, numbers and symbols
Number
Only values
Date/Time
Date including time information
Currency
Dollar amounts
Autonumber
A number that increases automatically as each is added
Yes/No
Only one of two values (a checkbox to tick on/off)
OLE Object
Picture or video clip
Lookup Wizard
A drop down box that offers a list of options
Hyperlink
Web address that links a web page
Attachment
A file or document
