Trio Sudoku (Fun With Sudoku #78)

When it comes to the easiest Sudoku types, Trio Sudoku tops the list. I don't think that any other Sudoku type can be as easy as Trio Sudoku. In this Sudoku type, solving is divided into three separate parts where each part can be solved independently of the other and hence making the Sudoku easier by 1/3. Another interesting easy Sudoku type is Even Odd Sudoku, in which Sudoku is divided into two parts with every part solvable independently. This is my second Trio Sudoku, with the first Trio Sudoku published with the title Trio Sudoku (Fun With Sudoku #71).

I am posting this Trio Sudoku as 78th Sudoku in the Fun With Sudoku Series. Can you solve this Trio Sudoku puzzle?

Rules of Trio Sudoku

Classic Sudoku Rules apply. Additionally, cells with circles must contain the digits 1, 2, and 3. Cells with squares must contain 4, 5, and 6. Blank cells must contain the digits 7, 8, and 9.