Define a function that removes duplicates from an array of non negative numbers and returns it as a result.
The order of the sequence has to stay the same.
Examples:
Input -> Output
[1, 1, 2] -> [1, 2]
[1, 2, 1, 1, 3, 2] -> [1, 2, 3]
def distinct(seq)
seq.uniq
end