(game "Hoshi" 
    (players 1) 
    (equipment { 
        (board 
            (union {
                (tri 3) 
                (shift 1 0.87 (rotate 180 (tri 3)))
                (shift 0 3.47 (tri 3))
                (shift -2 2.6 (rotate 180 (tri 3)))
                (shift -3 1.73 (tri 3))
                (shift -2 -0.87 (rotate 180 (tri 3)))
            })
            (values Cell (range 1 9))
        )
        (regions {0 3 1 4 2 5 7 6 8})
        (regions {17 16 14 15 11 13 10 12 9})
        (regions {18 19 20 21 22 23 24 25 26})
        (regions {27 28 29 30 31 32 33 34 35})
        (regions {36 37 38 39 40 41 42 43 44})
        (regions {45 46 47 48 49 50 51 52 53})
        (regions {36 39 41 43 44 33 31 28})
        (regions {47 37 40 42 35 34 32 30 27})
        (regions {51 49 46 38 18 21 23 25 26})
        (regions {53 52 50 48 45 11 19 22 24})
        (regions {0 3 5 7 8 15 13 10 20})
        (regions {1 4 6 17 16 14 12 9})
        (regions {53 52 51 49 47 37 39 41})
        (regions {0 50 48 46 38 40 42 43 44})
        (regions {1 3 5 45 35 34 33 31 29})
        (regions {2 4 6 7 8 18 32 30 28})
        (regions {17 16 15 13 11 19 21 23 27})
        (regions {14 12 10 20 22 24 25 26})
        (regions {2 4 1 3 0 50 52 51})
        (regions {17 6 7 5 45 48 46 49 47})
        (regions {14 16 15 8 38 40 37 39 36})
        (regions {9 12 10 13 11 35 42 43 41})
        (regions {20 22 19 21 18 32 34 33 44})
        (regions {24 25 23 27 30 28 31 29})
    }) 
    (rules
        (start <Challenge>)
        (play
            (satisfy {
                (all Different)
            })
        )
        (end (if (is Solved) (result P1 Win)))
    )
)

//------------------------------------------------------------------------------

(option "Challenge" <Challenge> args:{ <start> }
    {
    (item "1" 
        <(set {
            {53 5} {51 2} {48 3} {5 2} {1 3} {2 7} {17 5} 
            {14 1} {9 7} {13 4} {21 3} {24 6} {26 8} {21 3}
            {32 6} {28 2} {29 8} {42 9} {41 6} {36 5} {42 9}
        })>
        ""
    ) 
})

//------------------------------------------------------------------------------

(metadata
    (info
        {
        (description "Hoshi is a variant of Sudoku played on triangle basis.")
        (rules "Hoshi Sudoku consists of six large triangles. You must place the numbers 1-9 into the triangular cells of each large triangle. Every line, even an uncontinuous line, contains every number only once.")
        (id "1147")
        (source "<a href=\"http://www.cross-plus-a.com/sudoku.htm\" target=\"_blank\" class=\"style1\" style=\"color: #0000EE\" />cross-plus-a.com</a>")
        (version "1.3.13")
        (classification "puzzle/deduction")
        (credit "Eric Piette")
        }
    )
    
    (graphics {
        (board Colour OuterVertices (colour Hidden))
        (region Colour (sites {0 3 1 4 2 5 7 6 8}) (colour 148 220 212))
        (region Colour (sites {17 16 14 15 11 13 10 12 9}) (colour 220 156 204))
        (region Colour (sites {18 19 20 21 22 23 24 25 26}) (colour 204 228 116))
        (region Colour (sites {27 28 29 30 31 32 33 34 35}) (colour 172 220 220))
        (region Colour (sites {36 37 38 39 40 41 42 43 44}) (colour 220 180 156))
        (region Colour (sites {45 46 47 48 49 50 51 52 53}) (colour 204 204 228))
    })
)