MATLAB: Calculate the remaining index of the data

indexing

If i have
   x= 1 2       
      3 4
      2 5
      1 5
is the index of my data. i want to get on remaining of these index but not need index that have i=j i.e [ (1 1) (2 2) (3 3)(4 4)(5 5) and not need fliplr of x i.e [(2 1)(4 3)(5 2)(5 1)]. so i want to the result
   result=
       1 3
       1 4
       2 3
       2 4
       3 5
       4 5
that should not contain fliplr of any index.

Best Answer

Here is one way.
x= [1 2       
    3 4
    2 5
    1 5];
result = zeros(5*2,2);
ri = 1;
for ii=1:5
    for jj = ii+1:5
        result(ri,:) = [ii jj];
        ri = ri+1;
    end
end
isRowToRemove = ismember(result,x,'rows');
result(isRowToRemove,:) = [];
There is certainly a better way to pre-populate the array result with all possible row values than using the loops, but I got lazy.
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