1. Session Objectives# 24 COULD code the solution for an algorithm
SHOULD write pseudocode for an algorithm
MUST identify flow chart symbols
Recreate the solution in a high level language with a continue or exit clause.

2. Pseudocode Flow Chart Syntax Error Logic Error Algorithm IDE
Key Words
Key Words
Pseudocode
Flow Chart
Syntax Error
Logic Error
Algorithm
IDE

3. Flow Chart Symbols Revisited
Using white boards display what these symbols mean? 1. 2. 3. 4. 5.
START/STOP
Decision (IF or CASE
Statements)
Process either arithmetic ‘a + b’ or action ‘open file’
Input or Output
Subroutine symbol – a subroutine is like a program within the program. It is used to simplify complex flow charts

4. Flow Charts
KEY POINTS
Commands are in caps, variables in lower case e.g
Processes are generally a LET statement
Other constructs include: IF
process
ELSE
process 2
ENDIF or Loops (FOR –NEXT, REPEAT – UNTIL or WHILE – END WHILE)
Pseudocode
START/BEGIN
INPUT width
INPUT height
LET area = width * height
OUTPUT area
STOP/END
What will this programme do? Now write an algorithm for this programme
START
Input Width
Input Height
Area = Width x Height
Output Area
STOP

5. Creating Flow Charts & Pseudocode
Flow charts and pseudocode are methods of designing algorithms to solve problems. They are useful to make sure the logic of the algorithm is correct with no logic errors before starting to programme, when the programmer is then faced with the prospect of language specific syntax errors.
Logic errors – problems with the flow and structure of a programme
Syntax errors – problems with the spelling and punctuation of a programme.
TASKS:
Now turn to page 156 and complete tasks 1 – 4.
Extension Task 1 and the code a solution to any of your algorithms in Python. Aim to include a continue/exit feature.