Dog Sudoku Level 109 Hint
Find a bone with only two or three available neighboring cells, then test those cells against the row count, column count, and no-touch rule.
Dog Sudoku Level 109 Strategy
Hard Level 109 uses a 9x9 board with 10 bones. Use the row and column dog counts first, then resolve bones with limited neighboring cells.
Dog Sudoku Level 109 Solution
Solution dog cells: R1C1, R1C3, R1C6, R1C9, R5C1, R5C3, R5C7, R7C1, R8C3, R8C5.