Interview Questions – Unable to understand a coding program

Find possible length pairs of HCF and LCM from a single number
Example:

If you pass 4 its output should be like
 {0, 1}, {1, 0}, {1, 1}, {1,2}, {2, 1}, {2, 3}, {1, 4}
 Find out length of pairs

.

Someone helps me say which program wants to calculate, I could not understand the question.