I have a list that is obtained by flattening a matrix
list=Flatten[Table[{i, j}, {i, 1, 4}, {j, 2, 6, 2}], 1]
{{1, 2}, {1, 4}, {1, 6}, {2, 2}, {2, 4}, {2, 6}, {3, 2}, {3, 4}, {3, 6}, {4, 2}, {4, 4}, {4, 6}}
And I am looking for at way to reverse all "rows" with even numbers (the first element).
So that my list will look like this
{{1,2}, {1,4}, {1,6}, {2,6}, {2,4}, {2,2}, {3,2}, {3,4}, {3,6}, {4,6}, {4, 4}, {4, 2}}
Note that the first element stays the same, but the last element (for list with even first element) for the whole "row" has reversed.
Maybe there is an easy solutions to this, but I have not been able to find it yet.