Cat Sudoku Level 140 Hint
Find a colored region with only a few safe cells, then compare those cells against the row and column limits.
Cat Sudoku Level 140 Strategy
Hard Level 140 uses a 9x9 board with 9 colored regions. It starts without fixed cats, so the region shapes and no-touch rule do the work. Work from the tightest rows and regions before placing a cat.
Cat Sudoku Level 140 Solution
Solution cells: R1C9, R2C5, R3C3, R4C1, R5C4, R6C7, R7C2, R8C6, R9C8.