Book excerpt: Hidoku (from Hebrew: "my puzzle") is a logical puzzle.The goal of Hidoku is to fill the grid with consecutive numbers that connect horizontally, vertically, or diagonally.In every Hidoku puzzle, the smallest and the highest number are presented in the grid. There are more numbers on the board to help to direct the player on how to find the solution and to ensure that Hidoku has only a single solution.Hidoku puzzles are similar to Numbrix. The most important difference is that diagonal moves are allowed.