I would like to do the following:
A B
1 2
1 3
1 4
2 3
2 4
3 4
using data.table, but I am not sure how to exclude the already used numbers cumulatively.
I would like to do the following:
A B
1 2
1 3
1 4
2 3
2 4
3 4
using data.table, but I am not sure how to exclude the already used numbers cumulatively.