Impostors Example/Snack

The grid contains the digits 1-4, but normal 4x4 sudoku rules DO NOT apply. There are 4 impostor digits to be found, one in each row, column, and box.

Impostors: In each row, column, and box one digit has been removed and replaced by an impostor digit, which is a repeat of one of the other digits in that row or column. I.e. 1424 would be a valid example - 3 has been removed, and one of the repeated 4s is an impostor (the solver must deduce which one).

Each digit 1-4 appears exactly once in an impostor cell. The blue arrows is used to indicate the impostor digit in that row or column. Each digit 1-4 is removed from exactly one row, exactly one column and exactly one box. The red arrows is used to keep track of these. The blue and red arrows in the same row/column need to point to the same cell (the impostor).

Kropki dots: A black dot between cells indicates cell values with a 2:1 ratio. A white dot between cells indicates cells with consecutive values. Not all dots are shown.