Logic Masters Deutschland e.V.

This is my first puzzle with the highest difficulty level. Tricky, but solvable. :)

Try this puzzle on CtC Sudokupad

RULES:

• Normal sudoku rules apply: Fill the grid with the digits one to nine so that no digit is repeated in a row, column or region. (The empty space outside the given regions is not part of the puzzle.)
• Kropki rules apply: The values of cells separated by a black dot are in a 2:1 ratio. The values of cells separated by a white dot are consecutive.
• There is also a hidden snake in the grid. The snake is a 1-cell wide path of orthogonally and diagonally connected cells that covers the entire grid (54 cells). The snake is allowed to touch itself orthogonally and diagonally and can even cross itself with two diagonals in a 2x2 area. However, it is not allowed to re-enter a cell or region after leaving that particular cell or region. Therefore, it must always connect all nine cells of a region without interruption. Along the snake, the digits in each pair of adjacent cells must either be consecutive or in a 3:1 ratio. The first and the last digit on the snake's body have the same value.

NOTE: Make sure to enable the Pen Tool in the settings to draw the snake and keep track of its occupied cells.

NOTE: The Sudoku pad does not stop time when the puzzle is solved because technically not all of the cells are filled. But no worry. The solution code proves whether it is solved correctly.

Example: