Sudoku Solver in C++

Works for any correct Sudoku, otherwise it will display an error message.

• 0 = empty space
• numbers must contain spaces between them (no commas or anything else)
• after 9 numbers have been entered, press the "Enter" key and enter the next numbers with the same rules

Normal rules to solve apply:

• Each row must contain the numbers from 1 to 9, without repetitions
• Each column must contain the numbers from 1 to 9, without repetitions
• The digits can only occur once per block (square)
• The sum of every single row, column and block (square) must equal 45

1+2+3+4+5+6+7+8+9 = 45