Working out a Simple Example
Generally when trying to come up with an algorthim to solve a problem
you should consider the following steps:
- Break the problem into its sequential constituents.
- If parts of the problem depend on some condition being true
use an if <condition> then <statement> else <statement>
or simply an if <condition> then <statement>
as appropriate. If multiple
conditions exist with cooresponding actions then a nested
if ... then ...else statement must be used.
- Identify the parts of the problem that are repeated and
code the body of the loops first. Then put the appropriate
looping contruct around the body. Choose the looping construct
according to the following rules:
- User a for loop if you have a fixed number
of itterations. For example to repeat a process N times you
could use:
for i:=1 to N do begin <body of loop> end;
Note that you do not need to increment i as it is automaticaly
incremented at the ned of the loop.
- Use a while <condition> do loop whenever you
want to test some condition before each execution of the body
of the loop. Note that the body will only be executed whenever
the condition is true.
- Use a do <body> repeat <condition> loop
whenever you want the condition to be checked at the end of the
loop after the body has been exeuted. Note that the body will
always be executed at least once and the loop is repeated if
the condition is false.
Make sure that you choose the appropriate condition to ensure that
the loop is executed the required number of times.