Question about daily coding problem 1#

Question

Inside my code is a description. I don't understand what "Can you do it in one pass?" means.
https://code.sololearn.com/cV3VQCDiRGFL/?ref=app

Answer 1

If you want to do it in O(n) you can use Hashing.
https://en.wikipedia.org/wiki/One-pass_algorithm

Answer 2

I understand "one pass" as "one iteration" but I'not sure...!
🙈🙈🙈

Answer 3

Diego
Is this a one pass solution?

https://code.sololearn.com/cMoh3wz0S2oE/?ref=app

I have only one for loop to the get the numbers from the array. And a list. If the number is inside my list print true, if not add k-number to the list.
If I'm right I check every number only once. And I think that is the sense of one pass.

Answer 4

You can simply do
if (hash.contains(k-numbers[i]) == true){
// Code goes here
}

Answer 5

For bigger lists performance.
https://stackoverflow.com/questions/32552307/hashset-vs-arraylist-contains-performance
https://www.baeldung.com/java-hashset-arraylist-contains-performance

Same goes for hash.add(numbers[i]).

Answer 6

Coder What makes you think that? I think it is clear that I had only problems with the phrase "one pass". At no point did I write that someone should solve this challenge.

Answer 7

Diego Thank you :)

Answer 8

Diego And add numbers[i] ? Is there a difference?

Answer 9

What happens when I use other Lists, for example ArrayList instead of a HashSet?

Answer 10

Diego Thanks :)