How to efficiently remove duplicates from an array without using Set

Question

I was asked to write my own implementation to remove duplicated values in an array. Here is what I have created. But after tests with 1,000,000 elements it took very long ti

Answer 1

What if you create two boolean arrays: 1 for negative values and 1 for positive values and init it all on false.

Then you cycle thorugh the input array and lookup in the arrays if you've encoutered the value already. If not, you add it to the output array and mark it as already used.