Collections

A geography teacher is searching CITIES. The city names are stored in a collection called CITES. The teacher just wishes to print out the names of the cities beginning with D.

TASK1: Construct pseudo code algorithm ( using correct IB notation ) to indicate how this can be achieved.  Please post your answer to Google Classroom

Stacks    LIFO: last in first out

Great for parsing / checking syntax Rules 

Given a string: “hello (hello is a greetng [sic] {“sic” is used when quoting a text that contains a typo (or archaic [and nowadays wrong] spelling) to show that the mistake was in the original text (and not introduced while copying the quote)})”

The string to parse is held in a collection of letters called LETTERS and you can use associated commands.  

Two arrays exist that contain OPENBRACKETS[ [, ( ,{, ]  CLOSEBRACKETS[ ], }, ) ]

MYSTACK is a stack initially empty and you may use  MYSTACK.push() , MYSTACK.pop() ,  MYSTACK.isEmpty()

Updated TASK2Construct a solution in both psudeo code and as a flow chart ( using correct IB notation ) and post to google classroom the algoritm will :

Check that all brackets match:

● Every opening bracket has a closing bracket

● Every closing bracket has an opening bracket

● Nested brackets match up: no “([)]”!

for flow chart use google draw or  flowgorithm.org

Queues   FIFO: first in first out

Controlling access to shared resources in an operating system, e.g. a printer queue

A queue of requests in a web server

(Stacks and queues both appear when an algorithm has to remember a list of things to do)

Further Reading ( if needed ) click here

Approved Notation

Pseudo Code in Examinations