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Japanese Sums + Magnets (1148)
Instruction:
Locate some magnets in the grid. Each magnet fills two square cells that touch along an edge; one cell must be marked with a "positive" (+) symbol and the other cell must be marked with a "negative" (–) symbol. Cells that share an edge cannot contain the same symbol. Magnets do not overlap each other, and some cells will be left empty (not filled by any magnet).
The grid is already divided into regions; each region has an area of 2 cells. (Note that region borders are drawn and cell borders are not.) Each region either fully contains a magnet or is left empty.
Also, place a digit from the specified list into each cell occupied by a magnet (to the right of the symbol) so that no digit appears more than once in each row or column. (Digits cannot repeat even if they represent different numbers; for example, –3 and +3 cannot both be in the same row or column.)
Numbers outside the grid (when given) indicate all sums of contiguous groups of at least one number (including "sums" of a single number) along that row or column, in positional order. These groups are separated by empty cells. A question mark (?) indicates an unspecified sum.