Problem Link : https://www.codechef.com/ENFE2020/problems/ECFEB207

I think, we can decide some colours which are to be arranged in the first column, and then each of the selected colour should be present in the last column at least once in any order , and the rest of the (N) X (N-2) matrix can have any distribution with these selected colours, because now,no matter wherever we draw a vertical line , number of distinct colours in the two parts will be same…I couldn’t implement it. Can anyone please let me know, if this approach is correct and how can I implement it. Or suggest some better approach…