The task is to draw a single line ("snake") between marked cells; this line never touches itself, not even diagonally. Numbers outside the grid show how many cells must be blackened in the corresponding row or column.
The line must never cross itself, even diagonally.
Snake is a logic puzzle where you draw a continuous line (the snake) between two marked points on a grid. The line can't cross itself. Numbers outside the grid tell you how many cells to blacken in each row or column. The snake must pass through all empty cells that aren't black.