Computer algorithms are the rules to define what and how to do things. So to write algorithm for any type of program follow below mentioned steps.

1. STEPS FOR WRITING
ALGORITHM
“An algorithm must be
seen to be believed.”-
Donald Knuth

2. Determine the
Input/Output
• Have a good idea of what you are aiming to accomplish.
• Can be determined by taking note of steps to get there.

3. Decide on a
starting point
• Find a starting point for listing the steps of
process.

4. Find the
ending point
• Your algorithm must end
at some point otherwise it
will be incomplete.
• You should know where to
end.

5. List all the
steps
• From the starting point with the
inputs, list every small required step
to achieve the ending point and the
output.

6. Determine
how each step
will be
accomplished
• Think about how each steps can be
coded

7. Review the
algorithm
• Evaluate all the processes
and make sure that the
algroithm accomplishes
the correct output.