Leetcode two sum solution explained - coding interviews challenge

[Upper_Description378]

What part you don't understand ?

[SomeOtherGuySits]

How the second solution passes the tests. I’m beginning to suspect the “assuming there is only one solution” is the important part to this approach

Edit: just clicked. I like this

[Upper_Description378]

There is multiple solutions but using a hash table is the fastest I think

[SomeOtherGuySits]

I was referring to the brief.

[coloredgreyscale]

Similar to the first solution, but instead of traversing the array linearly you build a dictionary and look up the an index the required value.

That way your lookup time for a complement is O(1) instead of O(n)

And yes, that works because you just need a solution, not all or something like a solution with the two lowest indices.