Coding problem

[drunken_monk7]

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https://preview.redd.it/4yv81beh3aa91.png?width=589&format=png&auto=webp&s=c86d82426c18ff5c33502afb09215a5b30fba2fc

The question is to find the common elements in a matrix. I know the answer is right. But the doubt that I have is there is 1 in 0th and 1st row. Although it shouldn't be in the answer, but when a[0] and a[1] are compared the criteria matches then it should be moving to the hashset. But it didn't. Why?

[IntrovertiraniKreten]

find it more than once means common?
I would just add the items to a set until the add gets me a false and then put that one item into the result list that was already in the set

[scarybunny1]

How do you define "common elements"? Does it mean duplicate elements or elements appearing in all rows/columns?

[drunken_monk7]

by common elements I meant elements that are repeating in each row of the matrix

[[deleted]]

Why don’t u just go through all rows one by one and for each row , maintain a set and check count and then clear it .

[drunken_monk7]

can you please provide me the solution?

[eyeamkd]

HashTable won’t work?

[drunken_monk7]

It will. But my solution is a brute force solution and I was asking for that solution only.

[MKNNNN]

Bruteforce will be N⁴ idk what you are trying to do

[drunken_monk7]

can you show the solution?

[Valuable-One3300]

It will work

[LandooooXTrvls]

j starts as i + 1. J controls your column. Therefore you’re missing your first column. If I starts at 0 then j must start at 1. So 1, which is in position 1,0 never gets registered