From a set of ints you have to create a list of closed intervals as tuples, so the intervals are covering all the values found in the set.

A closed interval includes its endpoints! The interval 1..5, for example, includes each value x that satifies the condition 1 <= x <= 5.

Values can only be in the...
A single value, that does not fit into an existing interval becomes the start- and endpoint of a new interval.