# Checking Sudoku - sufficient sums

Are the following condition sufficient for checking if solution of Sudoku with (extended output) is valide :

• sum of values in each row, column and subsquare is equal to 45 and
• sum of squares of values in each row, column and subsquare is equal to 285

By extended output I mean that the error could be made, such that each value could be from range <-1000,1000> for example. As you see it is some kind of generalization of possible output of sudoku, but rules of Sudoku are unchanged.

Yes, as shown in the question you link to, if you check all rows, columns, and subsquares with the $2^{k-1}$ weighting and get $511$ each time, you have a valid Sudoku. –  Ross Millikan Mar 11 '13 at 22:33
Otherwise the equations $x+y+z =45$ and $x^2+y^2+z^2=285$ have real solution see here.