TwoSum Java Code, HashMap approach. O^n HD

Find two such numbers that add to a given target sum. Time and space complexity explained.

[Limpuls]

This is the best explanation I have came across. I never understood how complements worked until I watched this

[saileshramesh]

Thank-you so much for such wonderful explanation, understood each and every line of code with perfection. Please continue posting many many such videos.

[hadiali]

Great Explanation.
Just an add-on thing, it's not passing for one condition when the array contains: [3, 2, 4] and target = 6.
It will return 0, 0 (instead of returning 1, 2)
In order to handle this case, just replace your if condition with this one:
if(h1.containsKey(target) && i != h1.get(target))

[VipinKumar-rvfw]

We can see that complement comes out to be same element nums[i] which is at index 0 in given case hence it returned 0, 0.
As a solution, one can check if complement == nums[i] //given we have no duplicates allow.
Second solution, as I can see is that this can happen only when the nums[i] is targetSum/2. In case we have no duplicates allowed, we can add an if statement nums[i] == targetSum/2 then continue to next index without doing anything.

PS: I am not sure of my solutions though, haven't coded them yet. Newbie to Java. Correct me if I'm wrong somewhere.

PPS: Nice explanation and implementation.

[abhiram]

how would, map if the array contains duplicates

[asahimojica]

Please explain to me how the .getMethod is returning the Key value. to my understanding, .get(key) is suppose to return the value.

[-YEDUKONDALU]

Good Explanation 😍😍
We have to Check other Condition in If loop i.e
& & map.get(compliment)!=i)

[gtxmax-q]

It would fail if the target value lets say is 2 and first element of the array is 2.
2

[avisinha]

Nice explanation mam.
I don't know why one gave dislike 😑