Fastest way to create strictly increasing lists in Python

Question

I would like to find out what is the most efficient way to achieve the following in Python:

Suppose we have two lists a and b which are of equa

Answer 1

a = [2, 1, 2, 3, 4, 5, 4, 6, 5, 7, 8, 9, 8,10,11]
b = [1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15]
print(sorted(set(a)))
print(sorted(set(b)))
#[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
#[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]