So I came across this problem and I would like to implement and idea that after removing values that are directly divisible by 3 and the pairs that add upto sum (divisible by 3), the rem. ones may have some kind of combination of elements with sum adding upto 3
Example:
arr = [1,1,1,1,1,2,2]
after two operations , pairs gets out [1,2],[1,2] with sum(%3==0)
rem = [1,1,1]
Now, how to know that rem array may have some combinations sum divisible by 3?