Merge two arrays and remove duplicate elements

[Kushal Upreti]

Merges two or more arrays and removes any duplicate values i.e. [1,2,3] & [2,3,4] & [4,5,6] = [1,2,3,4,5,6]
Can use Map or Set for implementing the solution in O(N) time complexity

[Kushal Upreti]

Can I start working on this snippet?

[Angelos Chalaris]

This already exists in the form of union.